Calflora Taxon Report

Amethyst | Colored

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

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

💡 If you find purple glass in a historical context, it likely dates to the turn of the 20th century and was originally crystal clear before being "sun-colored" by decades of exposure. APPENDIX E: CULTURAL RESOURCE ASSESSMENT Colored Amethyst

Manufacturers added manganese oxide to "mask" the natural green or aqua tint caused by iron impurities in the sand used for glassmaking.

This report examines glass, a specific type of historic artifact frequently used by archaeologists to date sites from the late 19th and early 20th centuries. Executive Summary SCA glass is a critical diagnostic tool for

When exposed to sunlight (UV radiation), the manganese undergoes a chemical change, shifting the glass from clear to various shades of amethyst or violet. 2. Archaeological Significance

Beverage and medicine bottles are the most common finds. Tableware: Pressed glass dishes and decorative items. the manganese undergoes a chemical change

The purplish hue is the result of a specific manufacturing process:

Suggested Citation
“Calflora - Taxon Report.” The Calflora Database, a non-profit organization. .

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