sedimentary

Green Onyx (Agate)

Silicon Dioxide (SiO2)

Hardness: 6.5-7 Mohs; Color: Pale green with white and dark green banding/mottling; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None

Hardness: 6
Color: Pale green with white and dark green banding/mottling
Luster: Vitreous to waxy

Identified July 15, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 Mohs; Color: Pale green with white and dark green banding/mottling; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None

Formation & geological history

Formed as a cryptocrystalline variety of quartz, typically in the gas cavities (vesicles) of volcanic rocks or in cold-water spring deposits through the gradual deposition of silica.

Uses & applications

Commonly used for ornamental carvings (eggs, spheres), cabochons for jewelry, decorative household items, and lapidary art.

Geological facts

Despite being called 'Onyx' in the trade, most material of this type is actually a dyed or naturally translucent variety of Chalcedony/Agate. True onyx has parallel bands, whereas 'Green Onyx' specimens often show more cloud-like or random mottling.

Field identification & locations

Identify in the field by its waxy luster and hardness (it will scratch glass). Collectors look for uniform color or unique 'landscape' patterns within the stone. Commonly sourced from Brazil, India, and Madagascar.