Conchoidal fractures: Often results in a curved breakage surface that resembles ripples or waves across the surface of the stone. Similar to when you drop a stone in a lake. These ‘ripples’ are basically evidence of shock waves through the stone at the time of breakage. Glass, Obsidian, Beryl and Chrysoprase all break in this manner.
Vitreous Luster: Glass-like appearance.
Pseudomorph: A mineral that chemically repaces another without having an effect on the external form of the original material
Cryptocrystalline Structure: The crystalline structure is only visible when magnified.