mineral

Ruby, Emerald, and Sapphire (Corundum and Beryl)

Corundum (Al2O3) and Beryl (Be3Al2Si6O18)

Ruby/Sapphire: Hardness 9, Hexagonal crystal system, Adamantine to Vitreous luster. Emerald: Hardness 7.5-8, Hexagonal crystal system, Vitreous luster, Specific Gravity 2.76.

Identified January 23, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Ruby/Sapphire: Hardness 9, Hexagonal crystal system, Adamantine to Vitreous luster. Emerald: Hardness 7.5-8, Hexagonal crystal system, Vitreous luster, Specific Gravity 2.76.

Formation & geological history

Rubies and Sapphires form in metamorphic rocks like marble or igneous rocks like basalt. Emeralds typically form in hydrothermal veins or granitic pegmatites. Ages range from millions to over a billion years.

Uses & applications

Primarily used in high-end jewelry and as gemstones. Industrial-grade corundum is used as an abrasive or in laser technology.

Geological facts

The 'Big Three' gemstones. Ruby's red color comes from chromium, whereas Emerald's green is from chromium or vanadium, and Sapphire's blue is usually from iron and titanium.

Field identification & locations

Identified in the field by their distinct colors and high hardness. Found globally in locations like Myanmar, Sri Lanka (Corundum), and Colombia or Zambia (Emerald). Collectors look for clarity and saturation.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Green Apatite on Albite

Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]

mineral

Epidote

Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)

mineral