At a recent flea market, a woman approached my table where I had a variety of insulators for sale. She looked over my "ware" as if she was an experienced collector. Then she picked up the only sun colored purple insulator I had and remarked, "You sure know how to color these up pretty." This brings to mind that recently very little has been written about the glass that insulators are made of. As in this case, S.C.A. (sun colored amethyst) is the term collectors have applied. The authenticity of this glass is known to all collectors, but not too much has been said recently about what the glass is made of.

The basic composition of glass is soda ash, lime, limestone, and potash. From these are derived aqua or green insulator glass. Generally, the darker the aqua, the greater the quantity of iron and other impurities that have been mixed in the sand. It has been thought that the darker the color, the more iron it contained; thus, the stronger the glass. This dark color was fine for some customers, but others were more fussy and wanted more inconspicuous decolorized insulators, uniform in color. Manganese, a chemical when used in small quantities, produced a clear glass. "When used in large amounts manganese produces the amethysts, purples, and even black colors in glass." These dark colors are widely seen in several Canadian styles. On the other hand, some individuals have claimed that these dark colors were that way long before they were placed in service on a pole, and never affected by the sun. Manganese was a cheap way to decolorize cheap glass, but also very unstable. Its use is reported to have been discontinued around 1916 - 1918. It has been said that World War I cut off the supply of manganese from Germany. However, if World War I lasted from 1914 to 1918, whereas the well known Whitall Tatum Company was producing insulators from 1920 to 1938, how was it possible for so many thousands of SCA number one style to have been made? Strangely, in 1945 - 1946 , Hemingray produced the 54 A & B transposition in SCA. This was many years after the supposedly end of the use of manganese. Actually the war may have eliminated much use of manganese, but it continued until the development of the "continuous tank furnaces for making large quantities of glass became popular by glass companies". Then manganese became unpopular and too unstable for large batches.

Selenium later replaced manganese as a stable decolorizer. However, too much selenium produces pink colors, and in larger quantities, red glass can be produced. Gold can also produce red glass. Alfonso, the chemical cobalt can produce clear glass and a nice blue color in greater amounts. Combinations of different chemicals, cullet glass (glass and old bottles melted down to help form good glass). the way it was made, and even the firing temperature, make a difference in color of glass. Interesting reading can be further obtained from Sun Colored Glass by Mary J. Zimmerman and Insulators ... Just Insulators by Frank Saccoman.

Obviously, sun colored glass is glass that is colored by the sun. Or more exactly, ultraviolet rays from the sun interact with the manganese in the glass. The undesired color of the iron oxide present was being nullified by the manganese. This produces clear glass only because of an unfinished chemical process. Ultraviolet rays complete the process, thus producing the amethyst shades. The color was dependent on how much manganese was in the glass and how much sunlight it received. I have had many Tatum #1's from the Pacific Northwest in a light SCA. One summer on the roof of my house under the blaring Florida sun sure made a difference in some. Some folks have made "purple boxes" which use a germicidal lamp to produce UV rays instead of the sun. This lamp is very powerful and can accomplish what the sun can do in years, in a matter of months. It is also dangerous and can blind, so I do not fool with it. Some people use it for bottles or other glass, while others consider it cheating. I have seen some nice deep colored items come out of purple boxes, but generally the insulator will turn "all it is going to turn" up on top of the pole.

Along with artificially changing the SCA is heating it. Heat turns SCA glass back to its original near clear color. UV rays then can be applied to restore it to purple again. This cycle can be continued indefinitely. It has been said that some nice purple insulators have been put in a kiln and changed to a rare yellow color (a phoney), nearly back to its original clear. These may be some of the yellow California insulators. There are, however, sun colored amber insulators changed like the purple. These may be some of the light yellow no name beehives?

A few suggestions if you want to try sunning. Do it outdoors, such as on a roof, but not behind a window. The desert is a good place, but is not necessary, as bottle collectors well know. Your house does not have to be in sunny California, Arizona, or Florida. It can be anywhere there are many bright sunny days. Try putting a few on the roof for a few summer months. Check the difference. Some may change slightly, and others may have turned all they intend to turn. Be careful and be patient, as some will take time.