gemstone

Ruby in matrix (likely ruby-bearing corundum)

Corundum, aluminum oxide (Al₂O₃), chromium-bearing variety

AI-generated identification · may be incorrect

Deep pink-red, coarse crystalline and partly polished, with a contrasting brownish host matrix. Hardness 9 Mohs, vitreous to pearly luster, trigonal crystal structure, no distinct cleavage, and specific gravity about 3.9–4.1.

Identified September 10, 2026More gemstone →

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Physical properties

Formation & geological history

Forms when aluminum-rich rocks undergo high-grade metamorphism or in some basalt-related environments; chromium produces the red color. Ruby deposits range from Precambrian metamorphic terrains to younger alluvial concentrations.

Uses & applications

Used as a gemstone when transparent and attractive; opaque matrix specimens are mainly collectibles, ornaments, or lapidary material. Synthetic ruby is also used in lasers, watch bearings, and industrial abrasives.

Geological facts

Ruby and sapphire are both varieties of corundum; only red corundum is called ruby. Natural ruby commonly contains inclusions and may occur attached to marble, mica schist, or amphibolite.

Field identification & locations

Confirm with hardness testing, chromium-red coloration, and lack of cleavage, but avoid scratching valuable material. Common sources include Myanmar, Mozambique, Sri Lanka, Vietnam, Afghanistan, and Madagascar; this specimen appears to be a rough ruby-in-matrix piece.