Banded Agate (Carnelian type)

Physical Properties

Hardness: 6.5-7 on Mohs scale; Color: Reddish-orange with white banding; Luster: Waxy to vitreous; Crystal structure: Trigonal/Microcrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.64.

Formation & Geological History

Formed in cavities of volcanic rocks or ancient lavas, where silica-rich groundwater deposited layers of microcrystalline quartz over thousands of years. This specimen displays oxidation from iron impurities giving it a carnelian-like hue.

Uses & Applications

Used primarily in lapidary arts, jewelry making (cabochons and beads), ornamental carvings, and as a popular specimen for collectors.

Geological Facts

The banding in agates reflects the rhythmic fluctuations in the chemical environment during formation. It is one of the oldest gemstones used in jewelry, dating back to ancient Mesopotamia and Egypt.

Field Identification & Locations

Identify in the field by its waxy texture, translucency when held to light, and characteristic concentric or parallel banding. Commonly found in riverbeds, gravel pits, and volcanic regions.

Identified on: 4/19/2026

Mode: Standard