mineral

Agate

Agate (Silicon Dioxide, SiO2)

Hardness: 6.5-7 (Mohs scale), Color: Pinkish-red (carnelian agate) with white and gray banding, Luster: Waxy to vitreous, Crystal structure: Trigonal (microcrystalline/cryptocrystalline), Cleavage: None, Specific gravity: 2.58-2.64

Hardness: 6

Identified June 17, 2026More mineral →

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Physical properties

Formation & geological history

Formed as secondary deposits in cavities (vesicles) of volcanic rocks or sedimentary formations. Silica-rich groundwater percolates through voids, depositing layers of microcrystalline quartz over thousands of years.

Uses & applications

Commonly used in lapidary arts, jewelry (beads, cabochons), ornamental carvings, and as a semi-precious collector stone.

Geological facts

Agates are traditionally associated with healing and strength. The banding represents several generations of mineral growth, and many agates are named specifically for their locations (e.g., Lake Superior Agate).

Field identification & locations

Identify by its waxy luster, translucence when held to light, and characteristic concentric or moss-like banding. Common in volcanic regions and river gravels. This specimen appears to be a 'fairburn-style' or carnelian agate nodule with druzy cavities.