Indigo Gabbro

Physical Properties

Hardness: 6-7 (Mohs scale); Color: Mottled pattern of black, grey, and violet; Luster: Vitreous to dull; Crystal structure: Phaneritic (coarse-grained crystals); Cleavage: Good in two directions (due to feldspar and pyroxene)

Formation & Geological History

Formed from the slow cooling of magnesium-rich and iron-rich magma deep within the Earth's crust (plutonic). It is typically of various geological ages depending on the specific deposit location.

Uses & Applications

Primarily used as a decorative stone, semi-precious gemstone for jewelry, polished eggs or spheres for collectors, and occasionally used as a durable building material (dimension stone).

Geological Facts

This specific trade name 'Indigo Gabbro' or 'Mystic Merlinite' refers to a unique variety found in Madagascar that displays subtle violet hues when polished and under bright light.

Field Identification & Locations

Identify by its characteristic mottling and phaneritic texture. It is denser than granite. Commonly found in Madagascar, North America, and various oceanic crustal formations.

Identified on: 4/14/2026

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