- Chemical Formula: Fe2O3,
Iron Oxide
- Class: Oxides and Hydroxides
- Group: Hematite
- Uses: Very important ore of iron, as a pigment and as mineral
specimens.
Hematite has several varieties, each with their own unique names.
- Hematite Rose is a circular arrangement of bladed crystals
giving the appearance of the flower of a rose.
- Tiger Iron is a sedimentary deposit of approximately 2.2
billion years old that consists of alternating layers of silver gray
hematite and red jasper, chert or even tiger eye quartz.
- Kidney Ore is the massive botryoidal form and gives the
appearance of lumpy kidney-like masses.
- Oolitic Hematite is a sedimentary formation that has a reddish
brown color and an earthy luster and is composed of small rounded
grains.
- Specularite is a micaceous or flaky stone that is sparkling
silver gray and sometimes used as an ornamental stone.
Hematite is an important ore of iron and it's blood red color (in the
powdered form) lends itself well in use as a pigment. Hematite gets its name
from a greek word meaning blood-like because of the color of its powder.
Ancient superstition held that large deposits of hematite formed from
battles that were fought and the subsequent blood that flowed into the
ground. Crystals of Hematite are considered rare and are sought after by
collectors as are fine Kidney Ore specimens.
PHYSICAL CHARACTERISTICS:
- Color is steel or silver gray to black in some forms and red to
brown in earthy forms. Sometimes tarnished with iridescent colors when
in a hydrated form (called Turgite).
- Luster is metallic or dull in earthy and oolitic forms.
- Transparency: Crystals are opaque.
- Crystal System is trigonal; bar 3 2/m
- Crystal Habits include tabular crystals of varying thickness
sometimes twinned, micaceous (specular), botryoidal and massive. also
earthy or oolitic.
- Cleavage is absent however there is a parting on two planes.
- Fracture is uneven.
- Hardness is 5 - 6
- Specific Gravity is 5.3 (slightly above average for metallic
minerals)
- Streak is blood red to brownish red for earthy forms.
- Associated Minerals include jasper (a variety of quartz) in
banded iron formations (BIF or Tiger Iron), dipyramidal quartz, rutile,
and pyrite among others.
- Notable Occurrences especially nice specimens come from
England, Mexico, Brazil, Australia and the Lake Superior region.
- Best Field Indicators are crystal habit, streak and hardness.
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