Bloodstone
Image: James St. John (CC BY 2.0)
Mineral NameBloodstone
Chemical FormulaSiO2
Mohs Hardness7
Crystal Systemtrigonal
Lusterwaxy
Streak Colorwhite
Cleavagenone
Fractureconchoidal
Specific Gravity2.65
Colorsdeep green, deep red
Transparencytranslucent
Mineral GroupSilicates
Usesjewelry, carvings, ornamental stone
Raritycommon
Description
Bloodstone, also known as heliotrope, is a chert-like rock composed of cryptocrystalline quartz. It features a deep green base ('plasma') with distinctive spots, streaks, or patches of deep red ('jasper').
Geological Context
This variety of chalcedony forms as a secondary mineral in various geological settings, often in hydrothermal veins or as a component of sedimentary rocks, particularly those associated with volcanic activity.
