RocksdayLabradorite vs Moonstone
How to tell them apart
A gray plagioclase feldspar that flashes electric blue, green and gold when light hits it at the right angle.
Photo: Parent Géry, Public domain
A feldspar made of microscopic alternating layers that scatter light into a soft, floating blue-white glow called adularescence.
Photo: Didier Descouens, CC BY-SA 3.0
Key differences
- Labradorite is darker with vivid blue, green or gold flashes; 'rainbow moonstone' is actually white labradorite.
Side by side
| Property | Labradorite | Moonstone |
|---|---|---|
| Type | Mineral | Mineral |
| Mohs hardness | 6–6.5 | 6–6.5 |
| Luster | Vitreous | Vitreous to pearly |
| Streak | White | White |
| Colors | Gray, Black, Blue | White, Gray, Orange |
| Crystal system | Triclinic | Monoclinic |
| Specific gravity | 2.68–2.72 | 2.56–2.59 |
| Formula | (Ca,Na)(Al,Si)₄O₈ | (K,Na)AlSi₃O₈ |
| Found in | Labrador, Canada; Finland | Sri Lanka; India |
Properties that are the same for both are grayed out.
How to identify labradorite
- Dull gray until tilted — then a vivid blue/green flash.
- Fine parallel lines on cleavage faces.
- Hardness about 6.
- Flash only appears from one direction.
Crystal system: Triclinic
Full Labradorite guide →How to identify moonstone
- A milky glow that seems to float just under the surface.
- The glow moves as you tilt the stone.
- Flat cleavage faces on rough pieces; hardness about 6.
Crystal system: Monoclinic
Full Moonstone guide →More comparisons
Could you tell them apart from a blurry close-up?
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