mineral

Green aventurine or chrysoprase rough

Quartzite with fuchsite mica (aventurine) or chalcedony colored by nickel (chrysoprase)

AI-generated identification · may be incorrect

Green, opaque, fine-grained and roughly polished; vitreous to waxy luster. Aventurine is Mohs 6.5–7 with quartz grains and possible glittery mica; chrysoprase is microcrystalline quartz, Mohs 6.5–7, lacking cleavage, and typically has a waxy fracture.

Identified September 16, 2026More mineral →

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Physical properties

Formation & geological history

Aventurine forms when quartz-rich rocks recrystallize with chromium-bearing fuchsite; chrysoprase forms when nickel-bearing silica precipitates in fractures or weathered ultramafic rocks. These are generally young-to-ancient hydrothermal or weathering products rather than a single age-specific rock.

Uses & applications

Used as inexpensive cabochons, beads, carvings, ornamental stone, and lapidary material; rarely used in construction. Fine translucent chrysoprase can have meaningful gemstone value.

Geological facts

The image is not diagnostic enough to distinguish aventurine from chrysoprase; the dark matrix may be serpentine or another host rock.

Field identification & locations

Look for sparkly mica in aventurine, versus uniform translucent apple-green color in chrysoprase; a quartz hardness test and streak/glass-scratch test help, though they can damage the specimen. Common sources include India, Brazil, Russia, Australia, and Tanzania.