igneous
Indigo Gabbro
Gabbro (Alkali Gabbro)
Hardness: 6-6.5 Mohs. Color: Black to dark grey with indigo, violet, or blue-grey mottling. Luster: Vitreous to dull. Form: Phaneritic (coarse-grained). Composition: Plagioclase feldspar, pyroxene, and minor amphibole/olivine.
- Hardness
- 6-6
- Luster
- Vitreous to dull
Identified More igneous →
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Physical properties
Hardness: 6-6.5 Mohs. Color: Black to dark grey with indigo, violet, or blue-grey mottling. Luster: Vitreous to dull. Form: Phaneritic (coarse-grained). Composition: Plagioclase feldspar, pyroxene, and minor amphibole/olivine.
Formation & geological history
Formed through the slow cooling of magma deep beneath the Earth's crust (plutonic formation), typically in oceanic crust or deep continental margins. This specific decorative variety is primarily sourced from Madagascar.
Uses & applications
Mainly used for decorative purposes, lapidary arts, jewelry (cabochons), and as a popular stone among crystal collectors and metaphysical practitioners.
Geological facts
Commonly marketed as 'Mystic Merlinite' in the spiritual community, this stone is actually a coarse-grained igneous rock that formed at great depths and high pressures.
Field identification & locations
Identify by its characteristic 'patchy' or 'mottled' black and grey-violet texture. Unlike obsidian, it is crystalline and not glassy. Most high-quality specimens featuring the purple-blue tint are found in Madagascar.
