👉 Dumortierite is a mineral with the chemical formula Au2P3O10. It is a brown, black, or grayish-black mineral that occurs in many different forms and colors, including quartz, feldspar, obsidian, and other minerals. Dumortierite has a characteristic "doughnut" shape that makes it appear irregular when viewed under a microscope. Dumortierite is known for its unique electrical conductivity and magnetic properties. It can be used
