igneous
Labradorite (Larvikite variety)
Feldspar (Plagioclase series), (Na,Ca)(Si,Al)4O8
Hardness: 6-6.5 Mohs. Color: Grayish-black with blue/silver labradorescence (schiller effect). Luster: Vitreous to pearly. Crystal system: Triclinic. Specific gravity: 2.68-2.72.
- Hardness
- 6-6
- Luster
- Vitreous to pearly
Identified More igneous →
Explore Labradorite (Larvikite variety) 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: Grayish-black with blue/silver labradorescence (schiller effect). Luster: Vitreous to pearly. Crystal system: Triclinic. Specific gravity: 2.68-2.72.
Formation & geological history
Formed in plutonic environments from the cooling of magma at depths, resulting in large feldspar crystals. This specific variety is from the Larvik Plutonic Complex in Norway, dating back to the Permian period (approx. 290 million years ago).
Uses & applications
Extensively used as a decorative stone in architecture (façades and countertops), high-end jewelry (cabochons), and as a popular mineral for metaphysical collecting.
Geological facts
The 'blue flash' or labradorescence is not a surface color but a light interference effect from internal sub-microscopic layers created during the cooling of the rock. It is often marketed under the trade names 'Blue Pearl Granite' or 'Black Moonstone'.
Field identification & locations
Identify by rotating the stone in light to catch the metallic blue or silvery internal flashes. It is mostly found in the Larvik region of Norway. Collectors look for high 'flash' density and clarity of the blue hues.
