Out in the Sun

Solarized vessel exampleThis photo shows two pieces of the same vessel collected from a shovel test in West Virginia. The piece on the left shows evidence of solarization (the purple tint), while the piece on the right remains colorless. Manganese was used as a decolorizer in the glass making process to make the glass “colorless”.  Since Manganese is photo-sensitive and exposure to UV light alters the physical properties, the glass gains a purple/amethyst hue. The contrast in this image tells us the fragment on the right was buried without much exposure to sunlight, while the one on the left experienced prolonged exposure to sunlight before eventually being buried.