sedimentary

Chert (Heart-shaped Pebble)

Cryptocrystalline quartz (SiO2)

AI-generated identification · may be incorrect

Hardness: 7 on Mohs scale; Color: Tan to light grey; Luster: Dull to waxy; Crystal structure: Trigonal (microscopic); Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Tan to light grey
Luster: Dull to waxy

Identified May 17, 2026More sedimentary →

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Physical properties

Hardness: 7 on Mohs scale; Color: Tan to light grey; Luster: Dull to waxy; Crystal structure: Trigonal (microscopic); Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Formation & geological history

Formed through the precipitation of silica from seawater or the replacement of limestone by silica-rich fluids. This specimen was likely weathered and smoothed into its current shape by fluvial or glacial action.

Uses & applications

Commonly used as gravel, road surfacing, or abrasive media. Historically used for making tools like arrowheads due to its sharp edges when broken.

Geological facts

Chert is remarkably durable and resistant to chemical weathering. Heart-shaped 'love rocks' are popular finds for beachcombers and casual collectors due to their pareidolian appeal.

Field identification & locations

Identify in the field by its hardness (it will scratch glass) and its smooth, rounded texture from water erosion. Found in sedimentary basins and riverbeds worldwide.