Swiss blue topaz, 13x9 mm in a sterling setting $145 Made from Mt. St. Helens rock, these beautiful obsidian emeraldite earrings are 8x6mm in sterling settings. $135. These beautiful trillium shaped earrings are 8x8mm set in sterling settings. The Mt. St. Helens gemstones are made from the rock from the volcano and are called obsidian emeraldite. $195.