Selenite
Gypsum
What is Selenite?
Selenite is a variety of the mineral gypsum, which is a soft sulfate mineral composed of calcium sulfate dihydrate. It is known for its large, transparent crystals, often found in arid environments and caves. Selenite crystals can form in various habits, including tabular, prismatic, and fibrous forms. The name "Selenite" comes from the Greek word for "moon," reflecting its pearly luster and translucent appearance. It is often used for decorative purposes and in crystal healing practices.
Optical Properties
- Refractive Index
- 1.520-1.530
- Birefringence
- 0.009
- Pleochroism
- None
- Optical Character
- Biaxial positive
Discover Values
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Selenite Localities Map
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Quick Facts
Physical Properties
- Color
- Colorless, white, gray, yellow, brown, orange, and rarely green or blue
- Hardness (Mohs)
- 1.5-2
- Density
- 2.32 g/cm³
- Luster
- Pearly to vitreous
- Crystal System
- Monoclinic
Chemical Properties
- Chemical Formula
- CaSO₄·2H₂O
- Elements
- Ca, S, O, H
Also Known As
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