Crystal guide
How to Identify Labradorite
Plagioclase feldspar
Labradorite is a plagioclase feldspar flashing spectral colors (labradorescence) across a gray base. Identify it by dull gray stone that ignites blue-green-gold at one angle, Mohs 6–6.5, feldspar cleavage, and flash that rolls as you tilt.
About Labradorite
Labradorite is a plagioclase feldspar flashing spectral colors (labradorescence) across a gray base. Identify it by dull gray stone that ignites blue-green-gold at one angle, Mohs 6–6.5, feldspar cleavage, and flash that rolls as you tilt.
Labradorite is filed under crystals in the RockScan directory. Composition: Calcium-sodium aluminum silicate. It forms via mafic igneous rocks. Typical occurrence: Canada (Labrador), Madagascar, Finland (spectrolite). For the broader method, see how to identify rock types.
Labradorite properties
| Mohs hardness | 6–6.5 |
|---|---|
| Class | crystal |
| Scientific name | Plagioclase feldspar |
| Color | Gray base with spectral schiller |
| Luster | Vitreous |
| Crystal system / texture | Triclinic |
| Composition | Calcium-sodium aluminum silicate |
| Formation | Mafic igneous rocks |
| Occurrence | Canada (Labrador), Madagascar, Finland (spectrolite) |
How to identify Labradorite
- Gray base firing spectral blue-green-gold flash at one angle.
- Flash rolls with tilt across feldspar planes (labradorescence).
- Mohs 6–6.5; dull gray away from the flash angle.
Lookalikes to rule out
- Moonstone: Moonstone glows soft blue on a pale body; labradorite fires rainbow spectral colors across a gray base.
- Opal: Opal's play-of-color is fixed in patchwork with no cleavage; labradorite flash rolls across feldspar twin planes.
- Blue flash glass: Coated glass flashes uniformly with surface wear spots; labradorite flash comes from internal feldspar lamellae.
Photo tips for Labradorite ID
- Shoot at the flash angle — labradorite looks dull gray until the spectral plane catches light.
- Show both dead-gray and full-flash views of the same face; the contrast proves labradorescence.
- Polish faces photograph best; rough gray surfaces hide the flash entirely.
Snap one specimen in natural light, then open the result in the online studio or the rock identifier app.
Labradorite FAQ
How do you identify labradorite?
Tilt gray feldspar until rainbow flash ignites — that angle-dependent spectral fire is labradorescence. Moonstone glows blue on pale stone instead.
Labradorite vs moonstone?
Moonstone: soft blue billow, pale body. Labradorite: bold rainbow flash, gray body. Both are feldspars with different optics.
What is spectrolite?
High-flash Finnish labradorite with an unusually full rainbow — same mineral, premium optical grade.
How to identify labradorite
“Gray rock with hidden rainbow” searches almost always mean labradorite. The flash angle is the whole diagnosis:
- Gray base: dull medium-gray feldspar that looks ordinary away from the flash plane.
- Spectral ignition: blue, green, gold, sometimes full rainbow firing at one specific tilt.
- Rolling flash: colors sweep across twin planes as you rotate — fixed patches mean opal instead.
- Feldspar body: Mohs 6–6.5 with cleavage planes; coated glass shows surface wear, not internal lamellae.
- Photo confirm: dead-angle plus flash-angle pair of the same face, then RockScan against moonstone and opal.
Labradorite vs moonstone vs opal vs coated glass
- Moonstone: soft blue billow on pale stone; labradorite is rainbow fire on gray.
- Opal: fixed patchwork play-of-color in silica with no feldspar cleavage.
- Coated glass: uniform surface flash that scratches and wears; labradorite flash lives inside the stone.
Photo tips for labradorescence
Lock the camera, rotate the stone, and shoot the exact flash frame — plus one dead-angle frame for proof. Compare moonstone, opal, and quartz guides, then confirm in the online studio or rock identifier app.
Related crystals to compare
Browse all: rocks · minerals · crystals · directory · what rock is this · rock vs mineral vs crystal. Confirm with the online studio or rock identifier app.