sedimentary
Green Chert
Chert (Cryptocrystalline Quartz, SiO2)
AI-generated identification · may be incorrectHardness: 7 Mohs, Color: Olive to dark green, Luster: Vitreous to waxy, Structure: Cryptocrystalline, Fracture: Conchoidal, Specific Gravity: 2.6-2.7. It is opaque to translucent.
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Physical properties
Hardness: 7 Mohs, Color: Olive to dark green, Luster: Vitreous to waxy, Structure: Cryptocrystalline, Fracture: Conchoidal, Specific Gravity: 2.6-2.7. It is opaque to translucent.
Formation & geological history
Formed in marine environments from the accumulation of silica-rich organic remains such as radiolaria or diatoms. It can also form via chemical precipitation. Commonly found in sedimentary layers of deep-sea origin.
Uses & applications
Historically used for stone tools and arrowheads. Currently used as an ornamental stone, in aquarium decor, or as a lapidary material for jewelry like cabochons.
Geological facts
Green chert gets its color from chlorite or iron inclusions. Because of its conchoidal fracture, it was one of the most important materials for weapon-making in human prehistory alongside obsidian.
Field identification & locations
Identify by its extreme hardness (scratches glass), waxy luster, and shell-like (conchoidal) fracture edges. Commonly found in coastal areas or mountain ranges containing ancient seafloor sediment.
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