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www.mineralgallery.co.za Minerals F-J |
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Hematite |
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Name
Hematite
Chemistry
Fe2O3, Iron Oxide
Uses
Very important ore of iron, as a pigment and as mineral specimens
Color
Steel or silver gray to black in some forms and red to brown in earthy forms
Hardness
5.5 to nearly 7 depending on type.
Specific gravity
4.9-5.3
Spectacular hematite was discovered in May 1988 when hundreds of hematites were encountered.
These were associated with small red andradites garnets, calcites and barite. Tabular crystals from this pocket measured up to 30 cm diameter and 5-10 cm were common. But that is 10 years ago (1992) and those are now much sought after. Some crystals have bright metallic mirror-like surfaces. Magnificent. Hematite specimens date back to the early 1960' era with the discovery of the first rhodochrosites. Another type of hematite found was a botryoidal kind from Postmasburg area. These are also collectors items from this locality.
The widespread iron oxide, hematite is the most important ore mined to obtain iron. Other uses include polishing compounds and paint pigments. Varying in color from reddish brown to black, it forms brilliantly metallic, tabular crystals (see hexagonal system) and compact fibrous or granular masses and concretions. Found in rocks of all types as an alteration product of iron minerals, it is particularly abundant in sedimentary red beds. 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.
Spectacular hematite has been found in the Kalahari Manganese fields, particularly from the Wessels mine. Crystals up to 30 cm diameter, with mirror-silver surfaces are known, the most noteworthy "find" being made in May 1988 at the Wessels mine. Several hundred specimens were collected, many occuring as "floaters". Other outstanding specimens have also been found at the Black Rock, N'Chwaning I and N'Cwaning II mines
