Bloodstone
Quartz var. Heliotrope · Semi-Precious Gemstone
Crystal System
Trigonal - Hexagonal crystal system; typically found in cryptocrystalline massive habits with no visible external crystal faces.
Mineral Group
Silicates (Tectosilicate group, Chalcedony variety)
Chemical Formula
SiO2 with inclusions of Iron Oxide (Hematite) or Silicates (Chlorite)
Formation Process
Formed at low temperatures through the precipitation of silica from groundwater in the cavities of volcanic rocks (hydrothermal/sedimentary processes).
About This Crystal
An opaque, dark green variety of chalcedony quartz characterized by a waxy to vitreous luster. It features distinctive red to brownish-red spots or streaks caused by iron oxide inclusions. The specimen in the image appears as a tumbled, polished stone with deep forest green hues and darker mottled inclusions.
Physical Characteristics
Color: Dark green with red spots; Streak: White; Cleavage: None; Fracture: Conchoidal; Specific Gravity: 2.58–2.64; Tenacity: Brittle but tough due to microcrystalline structure; Fluorescence: Generally inert.
Optical Properties
Refractive Index: 1.544–1.553; Birefringence: Up to 0.009; Pleochroism: None; Diaphaneity: Opaque to occasionally translucent on thin edges; Optical Fenomena: None.
Hardness & Durability
Origin Region
India (primary source), Brazil, Australia, Germany, and the United States (California/Oregon). Often found in alluvial deposits or as nodules in volcanic rocks.
Hardness & Durability
Mohs Hardness: 6.5 to 7. Toughness is excellent due to the interlocking microcrystalline structure, making it highly durable for daily wear in jewelry like rings or pendants.
Care & Maintenance
Clean with warm soapy water and a soft brush. Avoid harsh chemicals, ultrasonic cleaners, and steam cleaners. Store separately from harder gemstones like diamonds or sapphires to prevent scratching.
Rarity & Value
Relatively common and affordable. Value is determined by the intensity of the green background and the distribution of vivid red 'blood' spots. Highly saturated specimens with distinct spotting are most prized.
Special Characteristics
The signature red inclusions (Hematite) create a 'splatter' effect that is unique to this variety of chalcedony. It does not exhibit common optical phenomena like chatoyancy or asterism.
Lore & History
Historically known as 'Heliotrope' (meaning 'Sun Turner'). In the Middle Ages, the red spots were believed to be the blood of Christ. Traditionally used as an amulet for protection, courage, and vitality. It is a traditional birthstone for March.