mineral

Banded calcite (onyx marble)

Calcite, CaCO₃; commonly sold as “honey onyx” or “Pakistan onyx”

AI-generated identification · may be incorrect

Cream-to-brown translucent, finely banded material with pearly to vitreous luster; Mohs hardness 3, rhombohedral calcite crystals, perfect rhombohedral cleavage, and specific gravity about 2.7. The visible parallel layers are characteristic of calcite deposited in veins or caves.

Identified August 10, 2026More mineral →

Explore Banded calcite (onyx marble) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Forms when carbonate-rich groundwater precipitates calcite in cavities, hot springs, or veins; most commercial material is geologically young compared with bedrock and is quarried especially in Pakistan, Afghanistan, Iran, Mexico, and Turkey. It is technically banded calcite, not true silica onyx.

Uses & applications

Used for ornamental carving, tiles, countertops, bookends, lamps, and polished specimens; it is too soft and cleavage-prone for most durable jewelry. Common polished pieces typically sell for $10–$60, with larger or especially translucent specimens around $100–$300.

Geological facts

Calcite effervesces strongly with dilute hydrochloric acid or vinegar, unlike quartz-based agate. It may scratch easily with a steel knife and can show strong optical doubling through clear areas.

Field identification & locations

Identify by its softness, layered cream-brown appearance, rhombohedral cleavage, and acid reaction; avoid confusing it with harder agate or marble. Common collecting and commercial localities include Pakistan, Mexico, and Turkey.