Colored Amethyst <PLUS · MANUAL>

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

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

When first produced, this glass appeared perfectly clear. Manufacturers added manganese oxide to "mask" the natural

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. this glass appeared perfectly clear.

💡 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

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

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