Semi-Precious Stones · uncommon
Moonstone
Moonstone is a feldspar mineral known for its adularescence—a billowy blue-white light that moves across the surface like moonlight on water.
Also known as: june birthstone, adularescence, feldspar gem.
Moonstone properties at a glance
| Type | Semi-Precious Stones |
|---|---|
| Chemical formula | KAlSi3O8 |
| Mohs hardness | 6 |
| Crystal system | monoclinic |
| Luster | vitreous |
| Streak | White |
| Cleavage | Perfect |
| Fracture | Uneven |
| Specific gravity | 2.6 |
| Transparency | translucent |
| Common colors | White, Gray, Peach, Blue sheen |
| Rarity | uncommon |
Geology & background
Forms in igneous and metamorphic rocks. The adularescence effect comes from alternating layers of orthoclase and albite.
Sacred in India for thousands of years, moonstone is traditionally given as a gift for the 13th wedding anniversary.
How to identify Moonstone
- Check whether the specimen's color and texture match typical Moonstone examples.
- Photograph a fresh surface in natural light and avoid shadows, glare, or wet surfaces.
- Use hardness, streak, luster, grain size, and locality together; no single trait is enough for every specimen.
Full Moonstone identification guide: checklist, home tests and look-alikes →
Moonstone vs similar stones
Not sure it isn't something else? Side-by-side comparisons with the stones most often confused with Moonstone.
Where Moonstone is found
Moonstone is reported from multiple localities or geological settings. Exact locality should be verified from specimen provenance, maps, or field notes.
How much is Moonstone worth?
| Entry-level specimen | $10 |
|---|---|
| Typical collector specimen | $50 |
| Premium specimen | $500+ |
Value depends on size, condition, color, crystal quality, locality, rarity, preparation, and provenance. Treat this as educational guidance, not an appraisal.
Common uses
- Jewelry
- Decorative objects
Interesting facts
- Ancient Romans believed it was formed from solidified moonlight
- The finest moonstones come from Sri Lanka
- Named Florida's state gem for the Apollo moon landings
Care & safety
Treat Moonstone as a collector specimen unless hardness, cleavage, and fracture are confirmed.
Avoid inhaling dust. Do not cut, grind, or polish unknown specimens without eye protection and a properly rated respirator.
Moonstone FAQ
What is Moonstone?
Moonstone is a feldspar mineral known for its adularescence—a billowy blue-white light that moves across the surface like moonlight on water.
How much is Moonstone worth?
Entry-level Moonstone specimens sell for around $10, a typical collector specimen for about $50, and premium pieces for $500 or more. Value depends on size, condition, color, crystal quality, locality, rarity, preparation, and provenance. Treat this as educational guidance, not an appraisal.
How hard is Moonstone?
Moonstone has a Mohs hardness of 6. It is about as hard as window glass: a knife barely marks it, while a steel file (Mohs 6.5) will.
Where is Moonstone found?
Notable sources of Moonstone include Sri Lanka, India, Madagascar, Myanmar, and USA. Forms in igneous and metamorphic rocks.
What is Moonstone used for?
Moonstone is used for jewelry and decorative objects.
