Staurolite is a red-brown to black mostly opaque nesosilicate mineral with a white streak. It crystallizes in the monoclinic crystal system has a Mohs…

Garnets (pronunciation: /ˈɡɑːrnᵻt/) are a group of silicate minerals that have been used since the Bronze Age as gemstones and abrasives. All species of…

Citrine is a variety of quartz whose color ranges from a pale yellow to brown due to ferric impurities. Natural citrines are rare; most commercial…

Emerald is a gemstone and a variety of the mineral beryl (Be3Al2(SiO3)6) colored green by trace amounts of chromium and sometimes vanadium.[2…