Carnelian
Carnelian is a brownish-red mineral commonly used as a semi-precious gemstone. Similar to carnelian is sard, which is generally harder and darker. Both carnelian and sard are varieties of the silica mineral chalcedony colored by impurities of iron oxide.
Carnelian is found in a number of Places throughout South Africa, and is also found in Zimbabwe, Namibia and Swaziland
Chemical Formular : SiO₂
Refractive Index : 1,54 – 1,55
Hardness : 7 on the Mohs Scale
Crystal System : Hexagonal