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Find out how to identify minerals (...and learn what shape, luster, color, streak, hardness, cleavage and fracture are all about!)
Meet some other nonsilicate minerals!
A sample of hematite may look like little more than a dark gray blob. That might seem impossible to identify but with a streak test, you can easily identify it! To tell if it is hematite, just rub the mineral against a white streak plate and it will form a small amount of red powder!
The largest amounts of hematite are found in sedimentary rocks that formed from weathering iron-rich minerals. In these sedimentary deposits, hematite is thought to have precipitated from lakes or seas by organic and/or chemical processes. The hematite often occurs with intermixed layers of quartz or chert.
Hematite is an important ore of iron. It is also used as a pigment in paint and in polishing compounds. It is made into a variety of handcrafted objects such as beads and jewelry.
- Shape: Trigonal (commonly occurs as tabular crystals)
- Luster: Metallic to sub-metalic to dull
- Color: Reddish-brown, gray to black
- Streak: Red
- Hardness: 5.5 to 6.5 on Mohs Hardness Scale
- Cleavage: None
- Fracture: Conchoidal
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TES XXVI, 3 fall 2010
The Fall 2010 issue of The Earth Scientist
, focuses on rocks and minerals, including articles on minerals and mining, the use of minerals in society, and rare earth minerals, and includes 3 posters!
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