Chert (Flint)
Silicon Dioxide (SiO2)
Category
Browse sedimentary (man made) specimens identified by the Rock Identifier community.
Chert (Flint)
Silicon Dioxide (SiO2)
Malaysian 50 Sen Coin
Coinage (specific alloy unknown without metallurgical analysis, but typically brass or bronze for this denomination and era)
Likely clear quartz crystal (possibly cut/polished quartz or glass imitation)
Quartz, silicon dioxide (SiO₂)
Chert (varietal: Flint/Jasper)
Silicon Dioxide (SiO2)
Sandstone
Arenite (composed primarily of Quartz: SiO2)
Coquina
Bioclastic Limestone
Coquina
Bioclastic Limestone
Sandstone
Arenite
Bog Iron / Limonite Concretion
Goethite/Limonite mixture (FeO(OH)·nH2O)
Weathered concrete or cementitious slab (not natural rock)
Artificial calcium-silicate cement composite; likely Portland cement concrete
Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
Chert (Chert / Flint)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline quartz (SiO2)
Chert (Yellow Jasper/Flint)
Silicon Dioxide (SiO2)
Coquina and Oyster Fossil Rock
Coquina limestone (Calcium Carbonate, CaCO3) containing fossilized Crassostrea / bivalve shells
Chert (Flint / Quartz Nodule)
Microcrystalline Quartz (SiO2)
Sandstone
Arenite (SiO2, often with CaCO3 or Fe2O3 cement)
Chert (specifically Tan/Gray Chert)
Microcrystalline quartz (SiO2)
Limestone
Calcium Carbonate (CaCO3)
Chert or Jasper
Microcrystalline Quartz (SiO2)
Chert (likely jasper/chalcedony-rich chert)
Microcrystalline quartz, SiO₂
Chert (often called Flint)
Chert (Cryptocrystalline Quartz, SiO2)
Coquina
Bioclastic Limestone
Flint
Silicon dioxide (SiO2)
Sandstone (specifically Arkose or Quartz Arenite)
Arenite (primarily SiO2 with possible Feldspar)
Green Aventurine
Quartz (SiO2) with Fuchsite inclusions
Chert / Flint
Silicon Dioxide (SiO2)
Tumbled cream-colored pebble
Likely quartz-rich sandstone or limestone; exact identification requires testing
Sandstone (Water-worn Cobble)
Arenite (SiO2 with CaCO3 or Fe2O3 cement)
Chert (Siltstone / Flint)
SiO2 (Cryptocrystalline Quartz)
Jasper
Silicon dioxide (SiO2) with impurities
Chert (Flint)
Silicon Dioxide (SiO2)
Slate
Metamorphic Pelitic Rock
Chert (Chalcedony/Agate variety)
Silicon Dioxide (SiO2)
Chert (with Quartz)
Microcrystalline Quartz (SiO2)
Conglomeratic concrete or asphalt aggregate surface with dark bituminous chunks
Polymictic gravel aggregate; dark pieces likely bitumen/asphalt, not a natural rock
Chert (Flint)
Silicon Dioxide (SiO2)
Chert Arrowhead (Jasper)
Chert (Cryptocrystalline Quartz, SiO2)
Sandstone
Arenite (siliciclastic sedimentary rock composed mostly of quartz)
Porous limestone (likely fossiliferous or weathered limestone)
Calcite-rich limestone; chiefly calcium carbonate (CaCO₃)
Chert / Flint
Silicon Dioxide (SiO2)
Chalk
Micrite (primarily Calcium Carbonate or CaCO3)