mineral
Moonstone (Tumbled)
Orthoclase (Potassium Feldspar) - (K,Na)AlSi3O8
Hardness: 6-6.5 Mohs. Color: Creamy white with blueish adularescence. Luster: Vitreous to pearly. Crystal Structure: Monoclinic. Cleavage: Perfect in two directions. Specific Gravity: 2.56-2.59.
- Hardness
- 6-6
- Color
- Creamy white with blueish adularescence
- Luster
- Vitreous to pearly
Identified More mineral →
Explore Moonstone (Tumbled) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-6.5 Mohs. Color: Creamy white with blueish adularescence. Luster: Vitreous to pearly. Crystal Structure: Monoclinic. Cleavage: Perfect in two directions. Specific Gravity: 2.56-2.59.
Formation & geological history
Formed in igneous and metamorphic rocks through the slow cooling of magma where orthoclase and albite separate into microscopic layers. These layers cause the characteristic scattering of light known as adularescence.
Uses & applications
Primarily used as a gemstone in jewelry, decorative ornaments, and highly valued by mineral collectors for its unique optical effects.
Geological facts
The 'glow' of moonstone is caused by light reflecting off alternating layers of two different feldspar minerals. In ancient Rome and India, it was believed to be created from frozen moonlight.
Field identification & locations
Identify by its 'adularescence' (a blueish sheen that moves across the surface). Commonly found in Sri Lanka, India, Myanmar, and Madagascar. Look for the characteristic light-play when tilted under a direct light source.
More like this
Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Schist
Schist
Metamorphic
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Gypsum (variety Selenite or Alabaster)
Calcium sulfate dihydrate (CaSO4·2H2O)
Mineral
Nephrite Jade
Nephrite
Mineral/Rock
Granite
Granite (Phaneritic intrusive igneous rock)
igneous