What is the common name of a biological sedimentary rock composed of microcrystalline silica (SiO2) originally formed as shells of living diatoms and radiolarian plankton, compressed into hard, flaky rock that can be used to make tools
Chert is a sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO2). It occurs as nodules, concretionary masses, and as layered deposits.
