helenite

== English == === Alternative forms === Helenite === Etymology === From Helen +‎ -ite. From Mount St Helens, whose volcanic ash is used to manufacture helenite. === Noun === helenite (uncountable) A greenish artificial gem, made by melting and vitrifying volcanic ash from the 1980 eruption of Mount Saint Helens. ==== Synonyms ==== Mount St. Helens obsidian