sedimentary
Chert
Microcrystalline Quartz (SiO2)
Hardness: 7 (Mohs scale), Color: tan to gray with waxy luster, Structure: microcrystalline, Fracture: conchoidal or irregular
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Physical properties
Hardness: 7 (Mohs scale), Color: tan to gray with waxy luster, Structure: microcrystalline, Fracture: conchoidal or irregular
Formation & geological history
Biogenic or chemical precipitation of silica in marine environments, often as nodules within limestone or chalk formations.
Uses & applications
Historically used for making stone tools (projectile points); currently used in road construction, landscaping, and as an industrial abrasive.
Geological facts
This specimen appears to be a worked piece of chert or flint, possibly a prehistoric projectile point or scrap flake, characterized by its sharp edges and silica content.
Field identification & locations
Can be identified by its extreme hardness (scratches glass) and shell-like fracture patterns. Often found in limestone outcrops or riverbeds.
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