igneous
Indigo Gabbro
Gabbro (MaFIC intrusive rock)
Hardness: 6-7 (Mohs scale), Color: Mottled black, grey, violet, and green with possible tan highlights, Luster: Vitreous to dull, Crystal structure: Massive/Phaneritic, Specific Gravity: 2.7-3.3
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Physical properties
Hardness: 6-7 (Mohs scale), Color: Mottled black, grey, violet, and green with possible tan highlights, Luster: Vitreous to dull, Crystal structure: Massive/Phaneritic, Specific Gravity: 2.7-3.3
Formation & geological history
Formed from the slow cooling of magma deep beneath the Earth's crust (intrusive). Most commercial specimens 'Indigo Gabbro' originate from Madagascar and are Precambrian to Cretaceous in age.
Uses & applications
Primarily used for ornamental purposes such as carved towers, jewelry (cabochons), palm stones, and within the metaphysical community as 'Mystic Merlinite'.
Geological facts
While marketed as 'Indigo Gabbro' or 'Mystic Merlinite', it is scientifically a gabbro containing quartz, feldspar, and various dark minerals like pyroxene or amphibole. Its unique color comes from a high concentration of dark minerals and feldspar.
Field identification & locations
Identify by its distinct mottled, 'stormy' appearance and high density compared to granite. It is commonly found in large plutons in Madagascar. Field identification relies on observing the coarse-grained phaneritic texture.
