Indigo Gabbro (Mystic Merlinite)
Gabbro (composed of plagioclase feldspar, pyroxene, and trace minerals like magnetite or ilmenite) · Decorative Stone / Semi-Precious Gemstone / Lapidary Material
Crystal System
Phaneritic (coarse-grained) igneous texture; individual minerals within the rock are Triclinic (plagioclase) and Monoclinic (pyroxene).
Mineral Group
Silicates; specifically a mafic intrusive igneous rock composed predominantly of calcic plagioclase and clinopyroxene.
Chemical Formula
Complex mixture: (Ca,Na)(Al,Si)4O8 (Plagioclase) + (Ca,Mg,Fe,Al)2(Si,Al)2O6 (Pyroxene)
Formation Process
Igneous: Formed by the slow cooling of magnesium-rich and iron-rich magma deep beneath the Earth's surface (intrusive plutonic environment).
About This Crystal
A polished sphere displaying a mottled, porphyritic appearance. It features high-contrast patches of light greyish-white (plagioclase) against a dark charcoal to black matrix (pyroxene). The luster is vitreous to slightly waxy when polished, and the texture is holocrystalline with visible grain boundaries.
Physical Characteristics
Color: Indigo-black, dark grey, and light grey; Streak: White to pale grey; Cleavage: Good (in feldspar grains) but not visible in rock form; Specific Gravity: 2.7–3.3; Fluorescence: Usually inert but plagioclase may show faint fluorescence.
Optical Properties
Opaque in mass, though thin edges of grains may be translucent; Refractive Index: N/A for rock mixture; typically exhibits no specific optical phenomena like labradorescence (distinguishing it from Larvikite).
Hardness & Durability
Origin Region
Mainly Madagascar (the primary source for the high-contrast 'Mystic Merlinite' variety); also found in volcanic/plutonic regions globally.
Hardness & Durability
Mohs Hardness: 6.0–7.0; Toughness: High (due to interlocking mineral structure); stable for jewelry and decorative use.
Care & Maintenance
Clean with warm soapy water and a soft cloth; avoids harsh chemicals or acids which can dull the surface of the pyroxene; store away from harder stones like Corundum.
Rarity & Value
Common; relatively affordable. Value is determined by the contrast of the 'indigo' spotting and the quality of the polish. Treatments are uncommon for this material.
Special Characteristics
The rock is often magnetic due to trace amounts of magnetite. The distinctive 'dalmatian-like' indigo and grey spotting is its most identifying visual trait.
Lore & History
Commonly marketed as 'Mystic Merlinite' in the metaphysical community. Historically, gabbro represents the deep crustal foundation of the Earth. It is traditionally associated with balancing light and shadow, grounding, and enhancing intuition in modern crystal lore.