Black Chert (Flint)
Microcrystalline Quartz (SiO2)
Category
Browse organic gemstone (sedimentary classification) specimens identified by the Rock Identifier community.
Black Chert (Flint)
Microcrystalline Quartz (SiO2)
Pearl (nacre)
Calcium Carbonate (mostly CaCO3 as Aragonite) and Conchiolin
Fossiliferous Limestone
Biogenic Limestone (CaCO3)
Glauconitic Sandstone (Greensand)
Glauconitic Quartz Arenite (containing Glauconite, (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)
Sandstone Concretion
Sedimentary Clastic Rock (Silicate-rich)
Limestone
Calcium Carbonate (CaCO3)
Bituminous Coal
Organic-rich sedimentary rock (Complex hydrocarbons)
Black Dolomite
Bituminous Dolomite (CaMg(CO3)2)
Chert / River Cobble
Microcrystalline Quartz (SiO2)
Glauconitic Sandstone (Greensand)
Glauconitic Sandstone (Iron-potassium phyllosilicate mineral: (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)
Chert (with Limestone matrix)
Silicon dioxide (SiO2)
Chert (variously known as Flint)
Microcrystalline quartz (SiO2)
Red Jasper
Jasper (Silicon Dioxide, SiO2)
Chert (Nodule)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Chert (SiO2)
Chert (Beach Pebble)
Microcrystalline Quartz (SiO2)
Chert Pebble
Chert (Silicon Dioxide, SiO2)
Chert
Microcrystalline Quartz (SiO2)
Chert / Jasper
Silicon Dioxide (SiO2)
Chert (Green variety)
Silicon Dioxide (SiO2)
Micro-crystalline Quartz Pebble (Chert)
Silicon dioxide (SiO2)
Chert (Flint)
Chert (SiO2)
Chert (Jasper/Agate)
Silicon Dioxide (SiO2)
Fossiliferous Limestone (Coquina)
Calcite (CaCO3) with Bioclastic inclusions
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Chert (with potential fossil inclusion)
Microcrystalline Quartz (SiO2)
Chert (often called Jasper or River Pebble)
Microcrystalline Quartz (SiO2)
Fossilized Crab Carapace (Concretion)
Decapoda (fossil), typically preserved in calcite or siderite concretion
Glauconitic Sandstone
Glauconitic Quartz Arenite
Chert (specifically Gray Chert/Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (with Quartz Vein)
Microcrystalline Quartz (SiO2)
Chert (Nodule)
Microcrystalline Quartz (SiO2)
Chert Nodules (with Flint core)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Chert (Flint Nodules)
Cryptocrystalline Quartz (SiO2)
Glauconitic Sandstone
Glauconitic Sandstone with high Glauconite concentration ((K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert / Greenstone
Silicon Dioxide (SiO2) with impurities
Chert (and Flint)
Chert (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)