Its crystals generate electricity when mechanically stressed.
Obsidian, olivine, and this mineral commonly exhibit conchoidal (con-COID-ahl) fracture. The interior of geodes almost always contains this mineral. Its crystals generate electricity when mechanically stressed. Herkimer diamonds do not contain diamonds but instead this mineral with Mohs hardness of 7. Citrine and amethyst are varieties of, for 10 points, what silicate mineral that is the most common on the Earth's surface?
Obsidian, olivine, and this mineral commonly exhibit conchoidal (con-COID-ahl) fracture.
quartz