Coal (likely Bituminous or Lignite)
Organic Sedimentary Rock (Carbonaceous)
Category
Browse organic mineraloid and mineral specimens identified by the Rock Identifier community.
Coal (likely Bituminous or Lignite)
Organic Sedimentary Rock (Carbonaceous)
Chert (Tan/Brown)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (containing Fossil Mold)
Silicon dioxide (SiO2)
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Chalcedony/Common Opal)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Banded Chert
Microcrystalline Quartz (SiO2)
Chert Pebble
Microcrystalline Quartz (SiO2)
Chert / Greenstone
Silicon Dioxide (SiO2) with impurities
Chert (variant Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (often called Flint)
Chert (SiO2)
Chert (with Limestone matrix)
Chert (Silica: SiO2)
Chert (Jasper/Chalcedony)
Microcrystalline Silica (SiO2)
Chert (Green variety)
Chert (Silicon Dioxide, SiO2)
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Fossil Coral (Rugose Coral Fragment)
Rugosa (extinct order of solitary and colonial corals)
Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (often called Flint or River Stone)
Chert (Microcrystalline Silicon Dioxide, SiO2)
Chert (and Flint)
Cryptocrystalline Quartz (SiO2)
Petrified Wood (Silicified Fossil)
Silicified Wood (SiO2)
Jasper
Jasper (Cryptocrystalline variety of Quartz, SiO2)
Chert (includes Flint & Jasper)
Chert (Siliceous sedimentary rock, chemical formula SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Chert (specifically Red Chert or Jasper)
Microcrystalline Quartz (SiO2)
Chert (Basanite variety)
Microcrystalline Quartz (SiO2)
Chert (varieties include Flint and Jasper)
Silicon Dioxide (SiO2) / Microcrystalline Quartz
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Jasper
Silicon Dioxide (SiO2)
Chert (Flint)
Microcrystalline Silicon Dioxide (SiO2)
Jasper (Petrified Wood Variety)
Silicon Dioxide (SiO2)
Chert (variations include Flint)
Chert (Silicon Dioxide, SiO2)
Chert (Flint)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Shungite
Non-crystalline carbon (similar to anthracite coal or meta-anthracite)
Pyritic Shale
Carbonaceous Shale with Iron Pyrite (FeS2)
Jasper
Silicon Dioxide (SiO2) with impurities
Fossiliferous Limestone
Calcium Carbonate (CaCO3) with Bioclasts
Fossiliferous Shale Matrix
Clastic Sedimentary Rock with Brachiopod or Mollusk shell fragments
Chert (Chert Nodule with Chalky Cortex)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Glauconite (Sandstone or Shale)
Glauconite (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2