Almandine Garnet in Matrix

Physical Properties

Hardness: 6.5-7.5 (Mohs scale); Color: Deep red to reddish-brown; Luster: Vitreous to resinous; Crystal structure: Isometric (often dodecahedral); Cleavage: None/Indistinct; Specific gravity: 4.1-4.3

Formation & Geological History

Formed during regional metamorphism of clay-rich sedimentary rocks (shale/mudstone) at high pressures and temperatures. Commonly found in mica schists or gneisses.

Uses & Applications

Used primarily as an abrasive (sandpaper, waterjet cutting), a gemstone for jewelry, and as a mineral specimen for collectors.

Geological Facts

Garnet is the birthstone for January. Almandine is the most common member of the garnet group and has been used since ancient Roman times for decorative inlays.

Field Identification & Locations

Identify in the field by its distinct 12-sided (dodecahedral) or 24-sided (trapezohedral) crystal habit, high hardness, and deep red color often embedded in a lighter schist or quartz matrix.

Identified on: 4/23/2026

Mode: Standard