Helenite, also known as Mount St. Helens obsiian, emerald obsidianite, and ruby obsidianite, is a synthetic gemstone made from the fused volcanic rock dust from Mount St. Helens, an American volcano located in the state of Washington. Helenite was made from the fusing of rock emitted from Mt. St. Helens during the catastrophic May 1980 eruption. In spite of its nicknames, helenite is not a true obsidian.