Feature Gems & Gemology, Summer 1986, Vol. 22, No. 2

Green Glass Made of Mount St. Helens Ash?

A specimen of green glass said to be made from ash from the May 1980 eruption of Mount St. Helens in Washington State was examined and compared with a black glass made by melting a sample of the ash. The glasses are quite different in their properties, and analytical results show that the green glass contains at most 5% to 10% of Mount St. Helens ash, if any.