Ruby in Matrix

Corundum (Al2O3)

Rock Type: mineral

Ruby in Matrix

Physical Properties

Hardness: 9 on Mohs scale. Color: Deep pink to blood-red. Luster: Vitreous to sub-adamantine. Crystal structure: Hexagonal/Trigonal. Cleavage: None, but exhibits parting. Specific gravity: 3.97-4.05.

Formation & Geological History

Formed in metamorphic rocks such as marble or schist, and igneous rocks like basalt. Created through high-pressure, high-temperature recrystallization of aluminum-rich minerals.

Uses & Applications

Primary use is in high-end jewelry as a gemstone. Industrial uses include lasers, watches (bearings), and scientific instruments due to extreme hardness.

Geological Facts

The red color of ruby is caused by the presence of chromium. It is the second hardest natural material known to man after diamond. Fine rubies can be more valuable than diamonds of similar size.

Field Identification & Locations

Identify by its distinctive hexagonal crystal habit, extreme hardness (will scratch almost any other mineral), and red streak. Commonly found in Myanmar, Sri Lanka, and Madagascar.

Identified on: 5/19/2026

Mode: Standard