1. SiO2Here's a question!
1.What is the chemical composition of this specimen?
2.What mineral does this specimen form from?
3.List three other minerals that have the same classification
btw sorry that I takes up the whole screen I don't know how to do the reveal button thing
2. It doesn't form from a mineral as it is a mineral, but I'm assuming you meant "what mineral is this a variety of," in which it is Quartz.
3. Amethyst, Agate, Chalcedony Also someone answer my question above.