mineral

Banded Onyx

Chalcedony (SiO2)

Hardness: 6.5-7 on Mohs scale; Color: Black with white or cream bands; Luster: Vitreous to waxy; Crystal structure: Hexagonal (Cryptocrystalline); Cleavage: None; Specific gravity: 2.6-2.65.

Hardness: 6
Color: Black with white or cream bands
Luster: Vitreous to waxy

Identified June 14, 2026More mineral →

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Physical properties

Hardness: 6.5-7 on Mohs scale; Color: Black with white or cream bands; Luster: Vitreous to waxy; Crystal structure: Hexagonal (Cryptocrystalline); Cleavage: None; Specific gravity: 2.6-2.65.

Formation & geological history

Formed by the slow deposition of silica in gas cavities (vesicles) in volcanic lava, creating distinctive parallel layers. Geological age varies by source location.

Uses & applications

Commonly used in jewelry (rings, pendants), carvings, cameos, and beads. Also valued in lapidary arts and as a collecting specimen.

Geological facts

Unlike agate, which has curved bands, onyx has parallel bands. The name comes from the Greek word 'onux', meaning claw or fingernail.

Field identification & locations

Identify by its smooth, waxy texture and straight, parallel banding. Commonly found in Brazil, India, Madagascar, and the US. Collectors look for high contrast between layers.