"Bottle/Glass Colors" Page -
Organization & Structure

The following glass color description categories are not in any significant order except that the list moves from the generally lighter to darker colors.  A user can either click on the color specific links below or just scroll down through the descriptions to find the color that you are interested in or that matches the color of a bottle you are trying to gain information on.

• Colorless (aka "Clear")
• Aqua (Aquamarine)
• Opaque White or Milk Glass
• Greens (non-olive) & Blue-greens
• Olive Greens/Ambers
• Amber
• "True" Blues
• Purple/Amethyst/Red
• Black Glass

Each color category discussion includes a general summary of how the color was produced, variations within the color category, pictures of bottles (with dating details) showing some of the variations, and an overview of the diagnostic utility of the color for dating and/or typing bottles.

Colorless (aka "Clear")

This color is the actually the absence of any color.  Colorless is preferred over the term "clear" or "white" glass since the former term refers more accurately to the transparency of the glass not its color, i.e., "clear green"; and the latter term implies milk glass which is discussed below (McKearin & Wilson 1978).  Colorless glass was a goal of glass manufacturers for centuries and was difficult to produce because it required the use of virtually impurity-free materials.  Venetian glass makers produced their crystallo as early as the 15th century and glass makers in 18th century England made what was known as "flint" glass from virtually pure quartz rock (calcined flint) which was simply called "flint" (Hunter 1950).  Improved chemistry and glass making methods of the late 19th and early 20th century allowed for process efficiencies that made colorless glass easier and much cheaper to produce with the use of various additives in the glass mixture.  The term flint glass was and still is used somewhat erroneously by glassmakers to describe colorless glass that is made with low iron sand.  It is, however, not true flint glass.  Flint glass is sometimes called lead glass (and vice versa) though true lead glass is made with lead oxide (Dillon 1958; Toulouse 1969a; McKearin & Wilson 1978).  Colorless glass was also called "crown" by early glassmakers (Hunter 1950).

Colorless glass is not always, or even usually, absolutely colorless.  It will usually have very faint tints of pink or "amethystine" (faintly visible in the base of the bottle to the left), amber or "straw", grayish green, grayish blue, or grey.  These faint colors are viewed easiest when looking through the thickest portion of the bottle, i.e., sideways through the base.  Colorless glass is usually attained by using the purest sand source possible and by adding "decolorizing agents" to the glass batch to offset the residual iron impurities (Dillon 1958).  Common decolorizing agents were manganese dioxide, selenium dioxide (usually in conjunction with cobalt oxide), and arsenious (arsenic) oxide which is also used as a stabilizer of selenium in decolorizing glass - or some combination of these compounds (Trowbridge 1870; Scholes 1952; Tooley 1953; Lockhart 2006a).

Colorless glass actually does have more utility in dating and typing than most other colors, though still of limited application.  Some of the better dating reliability is for bottles with manganese dioxide decolorized glass.  Upon exposure to sunlight, this glass will turn a light pink or lavender to moderately dark amethyst or purple depending on the amount of manganese and amount of ultraviolet (UV) light.   This is called "sun-purpled" or "sun colored amethyst " (SCA) glass.  The picture to the right shows a Johnson's Chill and Chill Tonic (Savannah, GA.) manufactured ca. 1900-1915.   This bottle began its life as colorless glass and has "turned" a much darker than average color of amethyst due to the exposure to (likely artificial) UV light (Kendrick 1968; Lockhart 2006b).  The light lavender tint produced by manganese offsets the green tint of the iron impurities in sand creating a largely colorless glass.

The Venetians apparently discovered by the 15th century that manganese could be used to decolorize glass.  Manganese became known as "glassmakers soap" due to the ability to "cleanse" or neutralize the effects of other impurities in the sand, particularly iron (Hunter 1950).   Manganese dioxide induced colorless glass was, however, by far most commonly used from the 1880s to about the end of World War 1.  At that time manganese dioxide use was greatly reduced for a variety of reasons, although largely because it did not work as well as other chemical decolorizers (see next paragraph) in the open continuous glass tanks used by the increasingly dominant bottle making machines - both semi-automatic and automatic.  It is often noted in the literature that the reason for the switch from manganese dioxide to other decolorants was due to the cut-off of German imports to the U. S. during WW1.  Although all imports from Germany (and Europe in general) were greatly constricted during this time, Germany was not a significant source of manganese for the U. S., providing only 2% of the imported manganese supplies in 1910 just prior to the war (Kendrick 1964; Lockhart 2006b).  It should be noted that occasional manganese dioxide decolorized bottles may date as early as the 1820s or as late as the 1930s (McKearin & Wilson 1978; Giarde 1989; Jones & Sullivan 1989; Lockhart 2006a & b), although the large majority of bottles made with manganese decolorized glass were made between about 1890 and 1920 (empirical observations). 

Colorless glass which was de-colorized with selenium or arsenic (or typically a combination of the two in conjunction with cobalt oxide) results in a very faint "straw" or amber tint to the thickest portions of the glass (Scholes 1952; Tooley 1953; Lockhart 2006b).  The picture to the left shows this color evident in the thick portion of a milk bottle (underneath the line pointing out the valve mark) that dates from between 1925 and 1930 based on a makers mark for the Pacific Coast Glass Company (Toulouse 1971).  Click Cloverdale Dairy Co. to see the entire bottle which was used by a dairy in eastern Nevada.  This colorless "color" can be very diagnostic of a machine-made bottle made from about 1912 to 1915 to typically no later than the 1950s (Girade 1989; Lockhart 2006b; empirical observations).  The straw tinted colorless glass in bottles does show up frequently in mouth-blown bottles but typically later ones (1900-1920), although can be found occasionally in bottles from the mid-19th century.  (Click French mustard bottle to view an 1870s era bottle with a faint straw cast - evident at the heel - to the otherwise colorless glass.)  Selenium was the best decolorizer for glass made in open glass tanks (versus the earlier closed pots) which was used with most all automatic bottle machines.  Like the colorless manganese dioxide glass, selenium decolorized glass will react slightly to UV light which produces or enhances the straw tint (Scholes 1952; Lockhart 2006a & b).

Diagnostic Utility:  Both of the above colorless glass tints can be useful diagnostic tools for an archaeologist who may be dealing with fragmental bottles.  One can be quite confident that if the fragment is colorless with a slight straw tint, it very likely is from a machine-made bottle, unlikely to date from much prior to World War 1 (i.e., mid-1910s), and could date as late as the mid-20th century (or later).  Conversely, a colorless fragment with a slight amethyst tint is quite likely to date to or prior to World War 1 (1915-1920) and is more likely than not to be from a mouth-blown bottle.  Bottles with a grayish tint seem to date between 1915 and 1925, although numerous examples outside that range have been noted by the author (Giarde 1989; empirical observations).  Generally speaking, bottles of colorless glass were relatively uncommon prior to the 1870s but became quite common after the wide spread use of automatic bottle machines in the mid to late 1910s (Kendrick 1968; Toulouse 1969a; Fike 1987; U. of U. 1992).  Nothing is absolute in these date range estimates, but they are believed to have reasonably high reliability.

As a side note, crown top soda bottles were generally not decolorized with manganese after 1914, giving a good ending date for such "colorless" bottles with an amethyst (manganese dioxide decolorized) cast to the glass as the beginning of World War 1; most of these type bottles would be mouth-blown (Lockhart 2006a & b).

Aqua (Aquamarine)

This color - like most of the colors that follow - had many subtle variations and shades.  Commonly used descriptive names for shade and color variations include blue aqua, green or greenish aqua,  pale blue aqua, and so forth.  The "gothic" or "cathedral" style pickle bottle (ca. 1870-1880) pictured to the left would be described as deep greenish aqua as it has a distinct light green color to the glass.  (Shades of aqua are a very common color for these utilitarian food bottles which were a common stylistic design particularly between the 1850s and 1880s though some examples date before or after that period.)  The term aqua is a preferred (by this website) shorthand version of the term aquamarine.  Use of modifying terminology is frequently employed to make more precise the color shape, intensity, or hue.  For example, the fruit jar pictured below would be considered deep blue aqua.

Aqua glass is a "natural" result of the iron impurities found in most sands.  It is very rare (maybe unknown) that sand does not contain some traces of iron.  Sand deposits with very low iron content were (and probably still are) highly valued commodities.  Although good quality sand was plentiful in the Eastern United States, some was still being imported from Belgium for Western American glass factories as late as the 1940s.  Aqua glass is the result of sand which is relatively low in the amount of iron which was not off-set by de-colorizing agents as noted in the colorless glass discussion above.  High levels of iron produce darker greens, black glass, and even amber.  Natural aqua glass was often called "green glass," "bottle glass," or "bottle glass green" by glass makers (Kendrick 1968; White 1978).

Different shades of aqua and the related blue-green colors which are often observed in the same bottles blown in the same mold may be explained - at least in part - by the following information quoted from Julian Toulouse's excellent book A Collector's Manual - Fruit Jars (1969a).  This excerpt is making reference to some of the effects - desired or not - that occur when mixing and melting glass.  It also points out one of the many complexities inherent in producing desired glass colors:

Diagnostic Utility: Aqua is a very common color in all types of American made bottles that date prior to the 1920s back at least to the early 19th century.  Thus, no specific type or class of bottles is more or less apt to have been made with aqua glass.  Aqua bottles became uncommon after the 1920s when colorless glass largely replaced aqua as the color of choice for bottle users wishing their product to be visible to the buyer (Miller & McNichol 2002).  The one significant exception to this dating is soda bottles, e.g., the greenish aqua of Coca-Cola bottles.  Shades of aqua color survived in soda bottles long after the 1920s and is still found today where glass is still utilized for soda containers. 

Another notable exception is that many fruit jars were also made well into the the 1930s in aqua though colorless glass probably became the majority color by about 1930.  Ball fruit jars were made in a distinct "Ball blue" from at least 1909 until at least the late 1930s and even later for some specialty items (Creswick 1987)).  The picture to the left shows two sizes of Ball's very popular Perfect Mason fruit jar.  This color is light but a more intense blue than blue aqua but does not quite fit the other color groups described below; thus its coverage here.  In 1939, the Ball Company was making 54.5 percent of all the fruit jars in the U.S. and the Perfect Mason was one of their most popular lines (Birmingham 1980).  This market domination during the first half of the 20th century explains the commonness of these fruit jars today and in historical sites from the early 1900s through the Great Depression.

Opaque White or Milk Glass

Opaque white glass - commonly called milk glass but sometimes called opal or white glass - was typically produced by the addition of tin or zinc oxide, fluorides (fluorspar), and phosphates (Illinois Glass Co. 1924; Dillon 1958; Kendrick 1968).  It was also created by adding calcium and phosphate rich animal horns, bones, and even "bat guano" to the glass batch (Trowbridge 1870; McKearin & Wilson 1978; Jones & Sullivan 1989).  In a sense, milk glass (the preferred term on this website) is like colorless glass in that it is defined by the absence of color, except in this case the bottle is truly not "clear".  An interesting feature of most milk glass is that very thin glass (i.e., fragment edge) has an orange-ish opalescence when held up to bright light.  It was also reputedly hard on the longevity of glass melting tanks and pots so was avoided by some glass factories.

Diagnostic Utility: Milk glass was used in the production of a wide array of different type bottles, though there is some typing and dating utility to the color.  The color was most commonly used in cosmetic and toiletry bottles (primarily from the 1870s to about 1920) and ointment/cream jars (1890s to the mid-20th century) (U. of U. 1992).  A typical cosmetic bottle example is the Owl Drug Company lotion (and likely other cosmetic products) bottle to the left which dates from the around 1895-1910 (Jensen 1967; Fike 1987).  Click milk glass Owl Drug with label to see an example with the original label showing that particular bottle contained "rose water" which was a distillate of rose petals used which was a type of natural perfume.  Many of the milk glass druggist type bottles were most likely for that particular druggist's cosmetic products as milk glass was well linked with cosmetics in customers minds (Fike 1987; Cannon 2004). 

Milk glass was occasionally, though uncommonly, used for ink, bitters, non-cosmetic medicinals, liquor, and sometimes even fruit and food jars primarily during the late 19th and early 20th century.  Milk glass is virtually unknown in the production of soda, mineral water, wine/champagne, and beer bottles.  It was rarely used for bottles prior to about 1870, i.e., milk glass bottles/fragments would not commonly be found on historic site's that date totally prior to the 1870s.

An interesting aspect of some milk glass is that it was made with manganese dioxide in the glass batch.  This milk glass will react to sunlight - as described in the colorless glass section above - producing a milky lavender color.  This has primarily been observed in cold cream and other cosmetic jars from the first couple decades of the 20th century, though it is seen in occasional bottles.  It sometimes appears that the lavender color was produced purposefully (with a UV light or radiation) so it is not always possible to differentiate between sun colored and intentionally colored lavender milk glass.

Greens (non-olive) & Blue-greens

There are probably more different shades of green to be found in bottles than any other color.  It rivals the multitude of amber glass variations which, as noted below, can grade into various greens.  The different greens were formed by a myriad of different coloring agents, impurities, and glass making processes.  Iron, chromium, and copper all produce different green glass.  Chromium oxide will produce yellowish green under oxidizing conditions and emerald green under reducing conditions in the glass furnace (Dillon 1958).  Combinations such as cobalt (blue) mixed with chromium (green) will, not surprisingly, produce blue-green glass (Kendrick 1968; Munsey 1970).

Just as there were many ways to produce different green glasses, there are endless naming variations for the green colors, e.g., blue-green, clear green,  peacock green, jade green, apple-green, emerald green, grass green, citron, etc.  As in describing all bottle colors, modifiers are useful in clarifying the specific greens.  For example, the flask to the left would be considered a medium blue-green with a slight slant towards the green end.  This early American (New England) flask has an eagle motif on one side, a Masonic emblem on the reverse, and was produced ca. 1815-1825 (McKearin & Wilson 1978). 

The mineral water to the right could be described as medium to dark emerald green.  This color is distinctive to mineral water bottles blown at the Congressville (NY) Glassworks and it and some subtle variations are known to collectors as "Congressville" green.  This particular Congress & Empire Springs bottle dates from about 1880-1885 as it has a true applied finish but also an earlier mold venting mark on the shoulder on each side of the bottle.  This distinctive style of bottle is often referred to as a "Saratoga" style (Tucker 1986).  See the Bottle Typing/Diagnostic Shapes page.

"7-up ®" green is a intensely brilliant green or yellow-green color that is associated with the famous soft drink bottle; their plastic bottles still use the color today.  The jar to the left is a medium density "7-up ®" green and was produced in 1940 based on the information derived from the Owens-Illinois Co. base markings (Toulouse 1971).

The soda/mineral water bottle to the right is in a color that could be described as a deep blue-green with a slant towards the blue end.  Compare this color to the medium blue-green (with a slant towards green) flask in the upper left corner of this box.  This bottle is from the Cottle, Post & Co. (Portland, OR.) and dates between 1878 and 1880 (Fowler 1975).  This bottle was produced during the era when applied finishes dominated, though it has an usual - for the time - tooled finish.  It was, however, not blown in an obviously air vented mold like the majority of molded & tooled finish bottles.

The flask below has a color that could be described as clear yellow-green or possibly light to medium emerald green.  This quart flask is a figured or pictorial Washington-Taylor flask (Philadelphia, PA.) which was likely blown during the 1860s (McKearin & Wilson 1978).

The bottle to the lower right is an example of what some call citron after the color of the fruit of that name.  This color is generally a "brilliant greenish yellow" like the pictured bottle though citron is sometimes described as a "brilliant...olive amber with yellow tone" (McKearin & Wilson 1978).  Another description would be "pale yellowish green with a slight golden cast" (Spurgeon 2004). The most commonly accepted definition of citron would be the first description and more or less, the color shown below.  This bottle is a Clement's Tonic (American or Australian) that likely dates between 1885 and 1900.  Citron is somewhat of a color bridge between the greens described here and the olive greens described next.

Diagnostic Utility: Different colors and shades of green can be found in just about any type or age of bottle providing no easily described diagnostic utility to this category of colors.  Some limited observations can be made however:

-The very bright "7-up ®" green is almost exclusively a 20th century feature as this bright of color is seen on very few 19th century bottles and then primarily the very late 19th century.  The mouth-blown "7-up ®" green prescription drug bottle in the middle of the bottle group picture at the top of this Bottle Colors page is a late handmade bottle dating from about 1915-1920.
-The "Congressville" green illustrated by the Congress Water in the upper right corner is a color that is most often seen on "Saratoga" style mineral water (and some soda water) bottles - primarily from the Eastern seaboard (Tucker 1986).  It is a color that was little if any used in the 20th century and only occasionally shows up in other types (non mineral water) of bottles - and then primarily 19th century items.
-Similarly, the blue-green colors shown above are very uncommon on machine-made bottles and generally denote a 19th or very early 20th century manufacture.

Olive Greens & Olive Ambers

These green colors are distinctly different enough from the greens described above to address separately.  There is also some dating and typing utility associated with the olive hues which is covered at the bottom.  The same green glass coloring agents were generally used to produce these olive colors; see information above.  Usually the olive greens and the related green colors were unavoidable or "natural" colors induced in the glass batch by variable levels of iron oxide naturally found in the sand.  These olive colors vary widely and grade into the other greens noted above as well as the amber colors which are discussed next.

There is also a myriad of descriptive names attached to the range of colors that have olive green as a significant component:  yellow olive, olive yellow, forest green, olive emerald, pea green, etc. are just some of the variations from the basic olive hue  As with other colors, the general degree of density and color can also be described with modifier terms like deep, dark, medium, light, bright, etc..

The unusual shaped bottle to the left in a brilliant olive green is likely a type of sauce bottle dating from around 1860 as the base has a glass-tipped pontil scar.  This color could be called olive-emerald green because of the inherent "brilliance" of the glass color.

The decorative or figured flask to the right is a medium olive amber in color.  This small (1/2 pint) New England made (Keene, NH.) sunburst flask was manufactured between 1822 and 1830 and is classified as GVIII-10 by McKearin & Wilson (1978).   This typifies an average olive amber color quite well as it is a fairly balanced proportion of both colors.

The flask to the left exhibits a rich bright greenish olive color which is often called forest green.  Forest green is a color variation that seems to be most commonly found in early (1800-1850) American made bottles and flasks with a color that is shifted more towards the green than the olive.  The pictured bottle is a "Pitkin" flask manufactured between 1790 and 1830 (McKearin & Wilson 1978).  The term "Pitkin" comes from the Pitkin, Connecticut glass works which is believed to have produced many of these distinctive flasks.  However, Pitkin style flasks were produced in a pattern mold using the "German half-post" method by many different glass makers in New England and the upper Mid-West during the early 19th century.  The name Pitkin has stuck however as the generic name for all of these flasks (Buckley 1985).

The bottle to the right could either be called a moderate olive green or possibly yellowish olive green, as there is a slight leaning towards a yellowish tone.  This small, relatively wide mouth bottle is an early American free-blown utility vessel which could have been used for anything from snuff to mustard to medicinals.  It likely dates between 1790 and 1820 (McKearin & Wilson 1978).

The small multi-sided bottle below left is a deep or dark olive amber with more amber than olive in the color.  It is an example showing where the olive color begins shifting towards amber colors.  The bottle is an eight-sided "umbrella" ink bottle of early (1830s to 1850s) New England manufacturing heritage.  The color could also be referred to as dark amber with an olive tone.

Diagnostic Utility: Different colors and shades of olive greens and olive ambers can be found in a lot of different types of bottles from different eras.  Generally speaking, olive green and particularly olive amber are colors which were much more commonly used in the 19th century than later the 20th - with some exception noted below.  It is also associated with certain types of bottles much more than other types.  Thus, there is some diagnostic bottle typing and aging utility with these colors based on empirical observations.  These of course are trends not absolutes, of which there are few in the world of historic bottle identification:

-Olive amber is a very uncommon color in any type bottle after about 1890 and almost unknown after about 1900.  After 1900 it is primarily found in wine/champagne bottles.
-Olive greens are very uncommon after about 1900 in most all types of American made bottles except some liquor bottles (e.g., scotch) and wine and champagne bottles which still are made in olive colors.  One observation is that the newer (after about 1920 or so) wine & champagne bottles tend to have a "brighter" olive green than the more subdued olive green prior to that time.  This color difference would only be evident with much experience looking at such bottles and is not absolute.
-The olive colors are most commonly found in the following type (age) of bottles: wine/champagne (any age), mineral water (1880s and before - particularly in the "Saratoga" types), ink (1880s and before), snuff (before about 1870), medicinals (1860s and before), beer & ale and all types of liquor (prior to 1910), figured flasks (prior to 1870), and some foods (1880s and before).
-Olive green and olive amber are uncommon colors for soda water bottles after about 1870 (not real common before that), canning jars, medicine bottles after the 1860s, perfume/cologne and druggist bottles at any time, and poison bottles.  (Covill 1971; Wilson 1972; McKearin & Wilson 1978; Zumwalt 1980; Tucker 1986; Odell 2000)

Amber

Various shades of amber in bottles was very common during the entire age span covered by this website - 19th through mid-20th centuries.  Like the greens, amber colors were produced from the natural impurities in glass (i.e., iron & manganese) as well as from color additives such as nickel, sulfur, and in particular carbon, which was added to the glass batch in the form of coal, charcoal, or even wood chips (Tooley 1953; Dillon 1958; Kendrick 1968).

As with the other major colors noted, there are many amber variations and names for those variations.  Commonly used terms include yellow, yellow amber, golden amber, red or reddish amber, honey amber, "old" amber (yellowish amber with a distinct greenish tint), olive amber (covered above), etc.  As with the other colors, the general degree of density and color can also be described with modifier terms like deep, dark, medium, light, bright, etc.

The quart beer bottle to the left is a typical medium amber color - not too dark and not too light.  It is a Buffalo Brewing Company (Sacramento, CA.) bottle that dates between 1890 and 1902.  The precise dating of this bottle was discussed on the Finish Types & Styles page - click Finish Types & Styles to review that discussion.

The unusual bottle with an applied handle to the right has a color best described as reddish amber; the reddish tint is subtle but distinct in the picture.  It is a Wharton's Whiskey (Philadelphia, PA.) that was was blown at the Whitney Glass Works (Glassboro, NJ) around 1860 (McKearin & Wilson 1978).  Applied glass handles were an unusual feature added to some fancy liquor bottles primarily during the mid-19th century (1850-1870), though a few were made to at least as late as the 1890s (Wilson & Wilson 1968).

The tall liquor bottle ("fifth" size) to the left is an example of what collectors call "old" amber.  More precisely this could be called a medium yellowish amber with an olive tint, though that makes the name quite a mouthful.  This particular "4-piece mold" whiskey/liquor bottle was most likely blown at the San Francisco & Pacific Glass Works (San Francisco, CA.) about 1880 based on diagnostic features (i.e., crudely applied finish, lack of air venting, color).  The bottle also has a distinctive eight pointed "star" (like an asterisk) on the base which has been widely attributed as a product of this Western glassworks (Zumwalt 1980).  Click SF&PGW star mark to view a picture of the base.

The quart fruit jar to the left is a very light yellow amber or just yellow, depending on ones interpretation of colors.  This is a mouth-blown Globe fruit jar which were first patented in May of 1886 and manufactured from that date probably into the early 1900s (Toulouse 1969a; Leybourne 2002).

Diagnostic Utility: Since amber colors were used for an extensive time period in most types of bottles, there is little dating or typing utility to the color.  However, a few thoughts on amber follow:

-Like olive amber discussed earlier, "old" amber is a color that is very uncommon in bottles made after 1890.
-In a related vein, when machine-made bottles dominated in the 1920s and glass making chemistry and techniques refined, amber became of a fairly standard tone and density.  That is, the off color ambers like yellow, yellow amber, and black amber (so dark that light hardly penetrates) become increasingly uncommon and a medium to medium dark amber - like the bottle pictured to the left - became the dominate amber shade.  The pictured machine-made beer bottle was produced by the American Bottle Company (Chicago, IL.) in the 1910s (Lockhart 2004).
-Amber was and still is the most common color for beer bottles as it provides the best light protection from the light wavelengths that are responsible for most photochemical reactions.  Too much light (natural or artificial) causes beer to become "light struck" which is a distinctive "skunky" off-flavor which is associated with green and clear bottled beer (Papazian 1991,1994).  Both of these latter colors provide little protection from the particular part of the spectrum which induce the off-flavor chemical reactions whereas amber glass provides a high level of protection (Dillon 1958).

"True" Blues

These variably moderate to intense blue colors are usually produced with the addition of the strong coloring agent cobalt oxide to the glass batch.  Copper could also produce types of blue glass depending on the batch ingredients and melting pot environment (Tooley 1953).

The various blue color shades and densities give rise to an assortment of names, with cobalt blue and sapphire blue being the most common covering the darker and lighter ends of the spectrum, respectively.  Dark sapphire is often used to describe medium cobalt blue; light cobalt blue is used to describe dark sapphire blue (McKearin & Wilson 1978).  Other descriptive names include: midnight blue (cobalt so dark it appears black without strong back lighting), cornflower blue (pale or very light sapphire), electric blue (a deep brilliant cobalt), and others.  However, the usual modifiers with the two main terms (cobalt and sapphire) are sufficient to describe most hues and densities of the "true" blue colors.  Blue-green colors were described under the "green" color section above.  "Ball blue" - the very distinctive light greenish blue color of 20th century Ball® fruit jars - was discussed in the "aqua" section.

The bottle pictured to the left above would be referred to as a medium cobalt blue.  It is an Owl Drug Company bottle (San Francisco, CA. & eventually nationwide) that was produced by the Whitall, Tatum & Company (Millville, NJ) between about 1895 and 1915.  These bottles reportedly held granulated citrate of magnesia and/or other products where a wider than average mouth (bore) was useful in dispensing the product.  One example observed by the author had a label indicating that that at least some (all?) specifically held "Granular Effervescent Phosphate of Soda" which was a laxative (empirical observations).

The medium sapphire blue bottle to the right is embossed on the front with Crystal / Soda  / Water Co. which was in San Francisco, CA.  These were almost certainly made at the San Francisco & Pacific Glass Works and date from between 1873 and 1886.  The applied finish on this bottle is somewhat of a modified blob with a slightly wider ring near the upper end of the lip.  This unusual bottle also has a pedestal base.  The actual closure for this bottle was likely a cork and the ring finish a stylistic feature like the base, though this is not known for sure.  Some versions of this bottle (but not this example) have a hole on opposing sides of the finish in which a metal pin was pushed through to secure the cork (Markota 1994).  The reverse side notes that the bottle and/or closure was a result of "Taylor's U.S. PT." (patent) which was "Patented Nov. 12, 1872."  Click Crystal Soda Water reverse for a picture of the reverse side of the bottle showing this embossing.

Diagnostic Utility: The presence of the various noted blue colors has limited dating and typing utility because of the wide application of the colors for various products.  Though not a common color when compared to aqua, amber, and the greens, cobalt and sapphire blue can be found to some degree in virtually any type of bottle from inks to figured flasks to beer bottles to even occasional food bottles (Covill 1971; Martin 1973; McKearin & Wilson 1978; Zumwalt 1980).  These blue colors are somewhat more common in certain classes of bottles like those intended for poisonous substances and cosmetics.  An example of the former would be the relatively common early 20th century Owl Drug Company poisons - click Owl poison bottle for a picture of an Owl poison.  These blue colors were also frequently used with soda and mineral water bottles from the 1840s into the early 1900s and ink bottles from from the 1840s into at least the 1930s (Schmeiser 1970; Covill 1971; Markota 1994).

Purple/Amethyst/Red

Purple, amethyst and red are uncommon colors in bottles but show up with enough frequency to warrant mention.  This group of purple to reddish colors were usually a result of glass that was colorized with nickel or manganese oxides (Tooley 1953) with true red usually a result of the use of oxide of gold (Hunter 1950).  As noted in the colorless glass description above, small amounts of manganese dioxide was used as a decolorizer to offset the iron impurities present in virtually all sands. This colorless glass will variably turn amethyst upon long term exposure to sunlight.  With larger concentrations of these substances in the glass batch amethyst to purple glass is purposefully created (Jones & Sullivan 1989).

Because of this color's variability (and popularity with collectors) it is not surprising that there are numerous names for subtle differences in this color theme.  They include descriptive words based on real reddish substances like claret, burgundy, red wine, or if tending towards amber, puce which according to Webster's Unabridged Dictionary (1996) is a "dark purplish brown to dark red."  The difference between purple and amethyst is subtle, though amethyst is often a "pinker" color than purple.  True red colored utilitarian bottles are very unusual and usually referred to as ruby red.

Diagnostic Utility: These true purple/reddish/amethyst colors (not sun colored amethyst) in bottles are primarily found in the era between the 1840s and early 1880s; they are rarely noted in bottles that date before or after that date range (empirical observations). 

The deep reddish amethyst colored bottle above left is a Mrs. S. A. Allen's World's Hair Restorer (New York) which dates from the 1870s.  Hair treatment bottles are one of the few classes of bottles in which the purple/amethyst colors are fairly commonly found.  Other classes of bottles where these colors occur with some frequency (though still not commonly) is figured or pictorial flasks, bitters (particular those which are "barrel" shaped like the bottle to the right), and some types of ink bottles.  The bottle to the right is an Old Sachem Bitters and Wigwam Tonic (New York) which likely dates 1860-1870.  It's color would be described as medium amethyst.  (This photo courtesy of Jeff Noordsy Antiques.)

True red - ruby red - utilitarian bottles are only known to the author as having been used for bottling Schlitz™ beer at various times - and in various period beer shapes - from the late 1940s to early 1960s (empirical observations).  An image of a Schlitz™ quart stubbie style beer bottle is to the left.  Click base view to see such showing the makers mark for the Anchor Hocking Glass Co. who made all of these esthetically colored bottles for Schlitz™.  The base photo also shows the "49" date code indicating production in 1949.  (Photos from eBay®.)

Black Glass

Black glass is probably "...the most important of the green glasses..." which "...was of so deep a color as to appear black in reflected light and even in direct light when the walls of the bottles were very thick..." according to McKearin & Wilson (1978:9).  This strong and resilient glass was also a color that offered the most protection to the contents from the effects of direct light.  Most black glass bottles are actually a very dark olive green or olive amber.  These types of black glass were the result of the same impurities or coloring agents as the olive colors - most usually high iron concentrations but also other substances including carbon (from various sources including ashes and coal clinkers), copper with iron, and magnesia (Jones & Sullivan 1989; McKearin & Wilson 1978).  Occasionally, black glass can be very dark amber ("black amber" - example shown later) or very dark reddish purple ("black amethyst"), although these types are not remotely as common as the olive color shades.  When the term "black glass" is used on this site, it is making reference to the very dark olive colors unless noted.

Black glass is one of the oldest bottle colors going back historically well beyond the time frames covered by this website - to at least the mid-17th century in Europe (Van den Bossche 2001).  Black glass beverage bottles (known as "junk bottles" by early glassmakers) and fragments are ubiquitous on historic sites that date prior to 1880 (McKearin & Wilson 1978:229-232).  Black glass liquor and ale/beer bottles "...were mass produced as a cheap container between the 1840s and 1880s...in a thousand shapes and sizes" (Wilson & Wilson 1968).  There is no measurable line delineating the point where olive green and olive amber become black glass except as noted at the beginning of this section as glass that appears "...black in reflected light..." (McKearin & Wilson 1978).

The accurate dating of late 18th and 19th century black glass containers is difficult for several reasons, most notably for the reason summarized by the following - "As late as 1880 the San Francisco glass houses were turning out (black glass) bottles as crude as those made in the east many years earlier, mainly because of unskilled labor and the inability to retain the workers" (Wilson & Wilson 1968).  In mid-19th century frontier California, where transportation costs from the east coast were prohibitive, the local glass makers enjoyed somewhat of a geographic monopoly.  This protective situation provided little incentive for glass makers to quickly adapt new methods for the production of cheap utilitarian wares such as black glass liquor and ale bottles.  This was not the situation on the east coast where glass makers had to fend off cheap imports from Europe, the amount of which flowing into the country was dependent on the level of tariffs and duties at any given time (Davis 1949).

The square, black glass (very dark forest green) bottle to the above left is a Hostetter's Stomach Bitters (Pittsburgh, PA.) that likely dates from between the late 1850s and mid-1860s. (Note: this bottle is also used as a dating example on the Examples page.)  Square bitters, large medicinals and liquor bottles - similar to the Hostetter's and in black glass - were a fairly common item made between the late 1840s and about 1870 (Switzer 1974; Wilson & Wilson 1968 & 1969).

The black glass (very dark olive amber) liquor or ale bottle to the above right is of early American origin being blown by the New England Glass Bottle Company (Cambridge, Mass.).  This company operated between 1827 and 1845 (McKearin & Wilson 1978).  The company name is embossed very faintly on the base of this bottle - click NEGBCo base marking to view a picture of the base.  The middle portion of the base has a sand pontil mark that is typical of that era.  This bottle is of very thick glass so that it is quite black even when backlit.

The very dark olive or "light" black glass bottle to the left is a snuff bottle that was most likely made in New England in the 1850s, as it has a glass tipped pontil scar on the base although it was unearthed in the Pacific Northwest.  This color is transitional between what is called black glass and very dark olive green though appears black in reflected light though not with moderate back lighting shown in the image.  These two colors are usually the same actual glass color with the black glass versions being either thicker glass or a denser tone.

Diagnostic Utility: American made black glass bottles of any type were uncommon after about 1880, making the presence of this color useful in the dating of archaeological sites (Wilson & Wilson 1968; empirical observations).  Even in imported bottles, black glass seems to disappear during the 1890s and those bottles that were earlier made in black glass are lighter in color after that time, i.e., medium olive green or olive amber (empirical observations), though as previously noted, there is no firm transition point from where the lighter colors end and black glass begins. 

The majority of black glass bottles made during the 19th century were for liquor or for wine and ale for which protection from the light was important in retaining quality.  This color is also found in pre-1870s ink bottles (ink bottles, ink wells and bulk inks), mineral waters (particularly the "Saratoga" types), snuff bottles, and some earlier medicinals and rarely for food bottles (empirical observations). 

Most of the dating and typing comments listed for the olive colors earlier on this page hold also for black glass except that black glass was little used in the 20th century for bottled products.  This includes wine, champagne, and liquor bottles which - in the 20th century - could be (if olive colored) of fairly dark olive green or olive amber glass but which would not meet the "black in reflected light" definition noted above (Covill 1971; Wilson 1972; McKearin & Wilson 1978; Zumwalt 1980; Tucker 1986; Odell 2000).  One notable exception to the last statement are the black amber soda bottles produced for Mission Dry Orange (soda) between 1929 and the mid 1930s.  The image to the right shows an example of these bottles which are discussed in more depth on the Soda & Mineral Water Bottles typology page.