6. While vacationing in the Smoky Mountains in North Carolina, you find a vein filled with a white mineral. (see pictures below). The mineral has a non-metallic, vitreous luster and a

conchoidal fracture. You cannot scratch it with a steel nail, but you can scratch it with a piece of topaz. What is the name of this mineral? How did it form (there are a few ways that the mineral could have formed in the vein- suggest at least one)?