Brown Agate

Physical Properties

Hardness: 6.5-7 (Mohs scale); Color: Variegated shades of brown, tan, and cream; Luster: Vitreous to waxy; Crystal structure: Hexagonal (cryptocrystalline); Cleavage: None, conchoidal fracture; Specific gravity: 2.58-2.64

Formation & Geological History

Formed in voids of volcanic rocks or ancient sedimentary formations through the slow deposition of silica from groundwater. This specimen appears water-worn or tumbled, likely from an alluvial deposit.

Uses & Applications

Commonly used for lapidary work, jewelry (beads and cabochons), home decor, and spiritual/metaphysical collecting.

Geological Facts

Agate is a variety of chalcedony that is defined by its banding or variegated patterns. Humans have used agate since the Neolithic era for ornaments and amulets.

Field Identification & Locations

Identify in the field by its translucency (when held to light), waxy feel, and lack of visible grains. Common in riverbeds and coastal areas globally.

Identified on: 4/28/2026

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