Rock Identifier

Category

Mineraloid (Organic)

Browse mineraloid (organic) specimens identified by the Rock Identifier community.

Chert (Brown variety) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Brown variety)

Silicon Dioxide (SiO2)

Chert (specifically Pink/Tan Chert) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Pink/Tan Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Fossiliferous Limestone (Crinoidal) (Calcium Carbonate (CaCO3) - Limestone containing bioclasts) — sedimentary

Fossiliferous Limestone (Crinoidal)

Calcium Carbonate (CaCO3) - Limestone containing bioclasts

Chert (Chert Pebble) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Chert Pebble)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Silicified Wood (SiO2 - Silicon Dioxide)) — metamorphic

Petrified Wood

Silicified Wood (SiO2 - Silicon Dioxide)

Chert (Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Quartz Variety) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Quartz Variety)

Silicon Dioxide (SiO2)

Chert (often called Flint or Jasper) (Chert (Microcrystalline or Cryptocrystalline Silica, SiO2)) — sedimentary

Chert (often called Flint or Jasper)

Chert (Microcrystalline or Cryptocrystalline Silica, SiO2)

Chert Pebble with Quartz Veining (Microcrystalline Quartz (SiO2)) — sedimentary

Chert Pebble with Quartz Veining

Microcrystalline Quartz (SiO2)

Chert (Jasper/Flint variant) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Jasper/Flint variant)

Silicon Dioxide (SiO2)

Banded Chert (River Siltstone) (Microcrystalline Quartz (SiO2)) — sedimentary

Banded Chert (River Siltstone)

Microcrystalline Quartz (SiO2)

Glauconitic Sandstone (Greensand) (Glauconitic Sandstone ((K, Na)(Fe3+, Al, Mg)2(Si, Al)4O10(OH)2)) — sedimentary

Glauconitic Sandstone (Greensand)

Glauconitic Sandstone ((K, Na)(Fe3+, Al, Mg)2(Si, Al)4O10(OH)2)

Chert (Arrowhead/Artifact Fragment) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Arrowhead/Artifact Fragment)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Fossil Coral (Favosites) (Favosites (Order: Tabulata, Phylum: Cnidaria)) — sedimentary

Fossil Coral (Favosites)

Favosites (Order: Tabulata, Phylum: Cnidaria)

Chert (specifically Gray/Blue Chert) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Gray/Blue Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Black Chert/Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Black Chert/Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Fossiliferous Limestone (containing Brachiopods) (Biogenic Limestone (Calcium Carbonate, CaCO3)) — sedimentary

Fossiliferous Limestone (containing Brachiopods)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Chert (varieties include Flint and Jasper) (Silicon Dioxide (SiO2)) — sedimentary

Chert (varieties include Flint and Jasper)

Silicon Dioxide (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Anthracite Coal (Anthracite (Carbon-based organic sedimentary/metamorphic rock)) — metamorphic

Anthracite Coal

Anthracite (Carbon-based organic sedimentary/metamorphic rock)

Picture Jasper (Silicon Dioxide (SiO2) with iron oxide and organic impurities) — sedimentary

Picture Jasper

Silicon Dioxide (SiO2) with iron oxide and organic impurities

Coal (Anthracite) (Anthracite (Carbon-based organic sedimentary/metamorphic rock)) — metamorphic

Coal (Anthracite)

Anthracite (Carbon-based organic sedimentary/metamorphic rock)

Pearl (Calcium Carbonate (CaCO3) - Aragonite/Calcite organic gemstone) — mineral

Pearl

Calcium Carbonate (CaCO3) - Aragonite/Calcite organic gemstone

Pearl (with Peridot) (Calcium carbonate (CaCO3) + Conchiolin; Peridot: Magnesium iron silicate (Mg, Fe)2SiO4) — mineral

Pearl (with Peridot)

Calcium carbonate (CaCO3) + Conchiolin; Peridot: Magnesium iron silicate (Mg, Fe)2SiO4

Chert (Brown variety / Common Jasper) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Brown variety / Common Jasper)

Microcrystalline Quartz (SiO2)

Red Jasper (Jasper (Silicon Dioxide with Iron inclusions - SiO2)) — Sedimentary/Metamorphic

Red Jasper

Jasper (Silicon Dioxide with Iron inclusions - SiO2)

Sedimentary/Metamorphic

Anthracite Coal (Anthracite) — metamorphic

Anthracite Coal

Anthracite

Chert (variously identified as Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (variously identified as Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Petoskey Stone (Hexagonaria percarinata (Fossilized Rugose Coral)) — sedimentary

Petoskey Stone

Hexagonaria percarinata (Fossilized Rugose Coral)

Septarian Nodule (Thunder Egg) (Septarian Concretion (CaCO3 + CaMg(CO3)2 + SiO2)) — sedimentary

Septarian Nodule (Thunder Egg)

Septarian Concretion (CaCO3 + CaMg(CO3)2 + SiO2)

Petrified Wood (Silicified Wood (primarily SiO2)) — sedimentary

Petrified Wood

Silicified Wood (primarily SiO2)

Chert (Tan/Grey variety) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Tan/Grey variety)

Silicon Dioxide (SiO2)

Chert (Iron-stained) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Iron-stained)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper/Flint variety) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Chert (often called Flint or Jasper locally) (Chert (Microcrystalline Quartz, Formula: SiO2)) — sedimentary

Chert (often called Flint or Jasper locally)

Chert (Microcrystalline Quartz, Formula: SiO2)

Petrified Wood (Silicified Wood (SiO2 - primarily Quartz/Chalcedony/Opal)) — Mineral/Fossil (Sedimentary context)

Petrified Wood

Silicified Wood (SiO2 - primarily Quartz/Chalcedony/Opal)

Mineral/Fossil (Sedimentary context)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Pearl (Calcium carbonate (CaCO3) + organic conchiolin (Biogenic Mineral)) — mineral

Pearl

Calcium carbonate (CaCO3) + organic conchiolin (Biogenic Mineral)

Slate (Slate (Foliated metamorphic rock)) — metamorphic

Slate

Slate (Foliated metamorphic rock)