sedimentary

Chert (Pink Jasper variant)

Microcrystalline Quartz (SiO2)

Hardness: 6.5–7 on Mohs scale; Color: Dull pink to dusty rose; Luster: Waxy to sub-vitreous; Crystal Structure: Trigonal (microcrystalline/cryptocrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.6–2.7

Hardness: 6
Color: Dull pink to dusty rose
Luster: Waxy to sub-vitreous

Identified April 1, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the accumulation of silica-rich organic remains (like diatoms or radiolarians) or chemical precipitation from hydrothermal fluids in sedimentary basins. This specimen appears weathered, likely from an ancient seabed or riverbed deposit.

Uses & applications

Historically used for stone tools (arrowheads/scrapers) due to conchoidal fracturing. Modernly used as decorative gravel, in lapidary work for tumbled stones, and as a collector's specimen.

Geological facts

Chert is one of the most durable sedimentary rocks. Pink variants often get their color from trace amounts of iron oxide (hematite) included within the silica matrix during formation.

Field identification & locations

Identify in the field by its hardness (it will scratch glass and steel) and its distinct shell-like (conchoidal) fracture pattern. It often has a smooth, waxy feel compared to surrounding sandstones or limestones.

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