sedimentary

Yellow Chert

Microcrystalline Quartz (SiO2)

AI-generated identification · may be incorrect

Hardness: 6.5-7 on Mohs scale; Color: honey-yellow, tan, or butterscotch; Luster: waxy to dull; Crystal structure: trigonal (microcrystalline); Cleavage: none (conchoidal fracture); Specific gravity: 2.65

Hardness: 6
Color: honey-yellow, tan, or butterscotch
Luster: waxy to dull

Identified July 4, 2026More sedimentary →

Explore Yellow Chert 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

Formed by the accumulation of siliceous remains of marine organisms or through chemical precipitation of silica-rich fluids in sedimentary rock cavities, often during the Paleozoic or Mesozoic eras.

Uses & applications

Used historically for stone tools and arrowheads due to its sharp fracture edges. Today used as an abrasive, in landscaping, and as a collector's specimen.

Geological facts

This specimen is a variety of flint. It was a primary material for prehistoric humans to create fire-starting kits and hunting tools because of its predictable fracture patterns.

Field identification & locations

Look for a waxy texture and conchoidal (shell-like) fractures. Commonly found in riverbeds, glacial tills, and limestone formations throughout the Midwestern United States and Europe.