Colored Amethyst -

Found in the ruins of late-Victorian and early-20th-century structures.

Beverage and medicine bottles are the most common finds. Tableware: Pressed glass dishes and decorative items. Colored Amethyst

Around the start of World War I, the supply of manganese (largely imported from Germany) was cut off. US manufacturers switched to selenium , which turns a straw or amber color when exposed to the sun, marking a distinct shift in the archaeological record. 3. Common Artifact Types Archaeologists frequently recover SCA in the form of: Found in the ruins of late-Victorian and early-20th-century

Manufacturers added manganese oxide to "mask" the natural green or aqua tint caused by iron impurities in the sand used for glassmaking. Around the start of World War I, the

Because manganese was the primary decolorizer used specifically from 1890 to 1920 , the presence of SCA shards helps researchers pinpoint the age of a historical site.

Sun-colored amethyst refers to glass that has turned a purplish tint due to prolonged exposure to ultraviolet (UV) light. This phenomenon is not natural to the glass's original state but is a chemical reaction involving manganese oxide, which was used as a decolorizer in glass production between approximately . 1. Chemical Composition & Origin

SCA glass is a critical diagnostic tool for cultural resource assessments and archaeological surveys.