Hematite
Hematite var. Kidney Ore · Mineral Specimen / Industrial Mineral
Crystal System
Trigonal; this specimen shows a massive and botryoidal (grape-like) habit with a rounded, bubbly surface.
Mineral Group
Oxides (Hematite group)
Chemical Formula
Fe2O3
Formation Process
Primarily sedimentary via precipitation from water, or hydrothermal through mineral-rich fluids in volcanic cavities.
About This Crystal
Opaque mineral with a metallic to sub-metallic luster on the rounded surfaces and a dull, earthy brownish-red luster in the fractured areas.
Physical Characteristics
Color is steel-gray to black with reddish tints; streak is characteristically reddish-brown; fracture is uneven to sub-conchoidal; specific gravity is 5.26.
Optical Properties
Opaque; high refractive index (~2.9); weakly pleochroic in thin sections, but generally appears metallic/shiny on the exterior surface.
Hardness & Durability
Origin Region
Cumbria, England; Morocco; and Michigan, USA are primary sources; found in sedimentary and hydrothermal environments.
Hardness & Durability
Mohs hardness of 5.5 to 6.5; brittle toughness; stable but sensitive to strong acids and localized physical impacts.
Care & Maintenance
Clean with warm soapy water and a soft brush; avoid ultrasonic cleaners; store separately to prevent scratching softer stones or being scratched by quartz.
Rarity & Value
Very common; value for botryoidal 'kidney ore' specimens is higher than massive hematite but remains affordable for collectors.
Special Characteristics
Displays a distinct 'kidney ore' botryoidal texture; non-magnetic unless heated; produces a red streak even if the stone appears black.
Lore & History
Historically used as red pigment (ochre) in cave paintings; traditionally associated with grounding, protection, and the root chakra in lore.