Hematite

Hematite

Hematite, 9.8 cm wide, Egremont, Cambria, England. California State Mining and Mineral Museum.
 

Composition: Fe2O3

Synonyms/Varieties:
Red Ocher
Specular Hematite
Turgite

Physical Properties:
Color: Steel gray and sometimes iridescent, dull red to bright red
Streak: Cherry red or reddish brown
Luster: Metallic to submetallic
Hardness: 5-6
Tenacity: Brittle
Specific Gravity: 5.26
Cleavage: None

Crystallography:
System: Hexagonal
Twinning: Common
Habit: Crystals are thin to thick tabular, rhombohedral, pyramidal, or rosettes. Aggregates are massive, compact, columnar, fibrous, reniform, botryoidal, stalactitic, micaceous to platy, granular, concretionary, oolititc and earthy. 

General Information:
Hematite is an iron oxide found in igneous, metamorphic and sedimentary rocks, and as an alteration product. Hematite can also precipitate in hot springs or in standing pools of water.
Hematite is commonly found massive and can form kidney-shaped rounded masses. It is also found as the red stain or coloring on rocks. When powdered, it was used as make-up. Also, Chinese doctors mixed it with clay to treat certain illnesses.
Name is from the Greek word aima, meaning blood, because of its resemblance to dried blood; or the Greek word aimatites, meaning bloodstone, because of the powder's red color. Known since antiquity.

Hematite on Mars:
http://marsrovers.jpl.nasa.gov/spotlight/hematite01.html

California Counties in Which this Mineral is Found
 

Calaveras
Fresno
Humboldt
Imperial
Inyo
Kern
Lake
Lassen
Mono
Placer
Plumas
Riverside
San Bernardino
San Luis Obispo
Shasta
 
Sierra
Sonoma
 
 

Information on Specimen Photo: Hematite, 9.8 cm wide, Egremont, Cambria, England.
California State Mining and Mineral Museum.
Photographer: Jeff Scovil