mineral

Tumbled quartz-rich carbonate rock

Likely massive quartz (SiO₂), possibly calcite-bearing marble or limestone

AI-generated identification · may be incorrect

Cream to white, opaque, waxy to dull luster, massive granular texture, and no obvious crystal faces. Quartz hardness is Mohs 7; calcite is Mohs 3 and fizzes with dilute hydrochloric acid, so hardness and acid tests can distinguish them.

Identified August 16, 2026More mineral →

Explore Tumbled quartz-rich carbonate rock 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

Likely formed through precipitation or recrystallization of silica/carbonate in a sedimentary or metamorphic setting; the specimen appears naturally rounded or mechanically tumbled. Exact geological age and origin cannot be determined from the image.

Uses & applications

Common quartz-rich material is used for aggregate, countertops, ceramics, glass, and decorative stone; attractive pieces may be sold as lapidary or display specimens.

Geological facts

The cream coloration may result from iron staining, clay, or carbonate impurities. Its irregular rounded form and cloudy interior are more consistent with massive quartz or quartzite than a clear quartz crystal.

Field identification & locations

Test with a steel nail or knife and inspect a fresh surface; quartz resists scratching, while calcite scratches readily and effervesces in acid. Common sources include quartz veins, hydrothermal deposits, and metamorphic terrains.