mineral
Selenite (Giant Crystals)
Selenite (CaSO4·2H2O)
Hardness: 2 (Mohs scale), Color: Colorless to white/pearly, Luster: Vitreous to pearly, Crystal structure: Monoclinic, Cleavage: Perfect, Specific Gravity: 2.3
Identified More mineral →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 2 (Mohs scale), Color: Colorless to white/pearly, Luster: Vitreous to pearly, Crystal structure: Monoclinic, Cleavage: Perfect, Specific Gravity: 2.3
Formation & geological history
Formed by hydrothermal fluids saturated with calcium sulfate slowly cooling over 500,000 years in stable temperatures (around 58 degrees Celsius).
Uses & applications
Used in plaster of Paris, wallboard, cement, soil conditioner/fertilizer, and as ornamental healing crystals.
Geological facts
The image shows the Cave of the Crystals in Naica, Mexico, home to the largest selenite crystals ever found, some reaching 12 meters in length and weighing 55 tons.
Field identification & locations
Identify by its softness (can be scratched with a fingernail) and crystalline transparency. Commonly found in Chihuahua (Mexico), Morocco, and the USA (Utah).
More like this
Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Nephrite Jade
Nephrite
Mineral/Rock
Banded Gneiss (River Rock/Pebble)
Gneiss (specifically a banded variety often found as a river rock)
Metamorphic Rock
![Green Apatite on Albite (Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]) — mineral](https://media.rockidentification.com/2391a63f-fb20-47d5-af9a-2035851eb32e-thumbnail.jpg)
Green Apatite on Albite
Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]
mineral
Epidote
Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)
mineral