Chert
| Colour | Gray, Brown, White |
|---|
What is Chert?
Chert is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO2). Chert is characteristically of biological origin, but may also occur inorganically as a chemical precipitate or a diagenetic replacement, as in petrified wood. Where chert occurs in chalk or marl, it is usually called flint.
How to identify Chert
Chert in different forms
Stones often confused with Chert
Frequently asked questions
How hard is Chert?
Chert's hardness varies; see the property table above.
What colour is Chert?
Chert is typically gray, brown, white.