Rock Identifier

Category

Organic Crystal (Mineraloid)

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

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

Jasper

Silicon Dioxide (SiO2) with iron oxide impurities

Chert (Iron-Stained) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Iron-Stained)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Amber (Cherry or Red variety) (Succinite (with various trace amounts of organic compounds)) — Organic Gemstone (not a rock)

Amber (Cherry or Red variety)

Succinite (with various trace amounts of organic compounds)

Organic Gemstone (not a rock)

Bituminous Coal (Organic-rich sedimentary rock (Complex hydrocarbons)) — sedimentary

Bituminous Coal

Organic-rich sedimentary rock (Complex hydrocarbons)

Chert (Flint) (Chert (Cryptocrystalline variety of Quartz, SiO2)) — sedimentary

Chert (Flint)

Chert (Cryptocrystalline variety of Quartz, SiO2)

Crinoid Fossil in Limestone (Crinoid (Class Crinoidea) in Fossiliferous Limestone (CaCO3)) — sedimentary

Crinoid Fossil in Limestone

Crinoid (Class Crinoidea) in Fossiliferous Limestone (CaCO3)

Chert (often colloquially referred to as Flint) (Chert (Cryptocrystalline Quartz, SiO2)) — sedimentary

Chert (often colloquially referred to as Flint)

Chert (Cryptocrystalline Quartz, SiO2)

Jasper (Mookaite variety likely) (Silicon Dioxide (SiO2) with iron oxide inclusions) — sedimentary

Jasper (Mookaite variety likely)

Silicon Dioxide (SiO2) with iron oxide inclusions

Banded Chert (Ironstone/Jasper) (Cryptocrystalline Quartz (SiO2) with Iron Oxides) — sedimentary

Banded Chert (Ironstone/Jasper)

Cryptocrystalline Quartz (SiO2) with Iron Oxides

Chert (Jasper variation) (Chert (SiO2)) — sedimentary

Chert (Jasper variation)

Chert (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Travertine (often colloquially called Tufa) (Chemical Sedimentary Calcium Carbonate (CaCO3)) — sedimentary

Travertine (often colloquially called Tufa)

Chemical Sedimentary Calcium Carbonate (CaCO3)

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

Chert (specifically Blue Chert or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Jasper (Jasper (Silica-rich microcrystalline Quartz, SiO2 with Fe2O3 impurities)) — sedimentary

Jasper

Jasper (Silica-rich microcrystalline Quartz, SiO2 with Fe2O3 impurities)

Chert (variant Flint/Jasper) (Microcrystalline Opaline Silica (SiO2)) — sedimentary

Chert (variant Flint/Jasper)

Microcrystalline Opaline Silica (SiO2)

Chert (Jasper variety) (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Chert (Jasper variety)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (often called Flint or Jasper depending on color) (Chert (SiO2 - Microcrystalline or Cryptocrystalline Quartz)) — sedimentary

Chert (often called Flint or Jasper depending on color)

Chert (SiO2 - Microcrystalline or Cryptocrystalline Quartz)

Orange Calcite (Calcium Carbonate (CaCO3)) — mineral

Orange Calcite

Calcium Carbonate (CaCO3)

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

Petrified Wood

Silicified Wood (primarily SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

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

Chert (Iron-stained)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Chert (often called Flint when dark) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (primarily SiO2 - Silicon Dioxide)) — mineral

Petrified Wood

Silicified Wood (primarily SiO2 - Silicon Dioxide)

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

Petrified Wood (Silicified Wood)

Silicified Wood / Silicon Dioxide (SiO2)

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

Petrified Wood

Silicified Wood (primarily SiO2)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Chert (Green variety) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Green variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Petrified Wood (Agatized/Silicified Wood) (Silicified Wood / Chalcedony (SiO2)) — sedimentary

Petrified Wood (Agatized/Silicified Wood)

Silicified Wood / Chalcedony (SiO2)

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

Chert (Flint Pebbles)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Amber (specifically Cherry Amber) (Succinite (with the chemical formula C10H16O)) — Organic Gemstone (not a mineral)

Amber (specifically Cherry Amber)

Succinite (with the chemical formula C10H16O)

Organic Gemstone (not a mineral)

Basaltic Tuff / Volcanic Breccia (Pyroclastic Breccia / Lithic Tuff) — igneous

Basaltic Tuff / Volcanic Breccia

Pyroclastic Breccia / Lithic Tuff

Stromatolite (Jasper-replaced) (Fossilized Stromatolite (Cyanobacteria / Cryptozon / Silica SiO2)) — sedimentary

Stromatolite (Jasper-replaced)

Fossilized Stromatolite (Cyanobacteria / Cryptozon / Silica SiO2)

Ironstone Concretion (Limonite/Hematite Nodules) (Ironstone (principally Limonite FeO(OH)·nH2O or Hematite Fe2O3 mixed with silica/clay)) — sedimentary

Ironstone Concretion (Limonite/Hematite Nodules)

Ironstone (principally Limonite FeO(OH)·nH2O or Hematite Fe2O3 mixed with silica/clay)

Quartz Geode (Silicon Dioxide (SiO2) within a secondary sedimentary structure) — sedimentary

Quartz Geode

Silicon Dioxide (SiO2) within a secondary sedimentary structure

Jasper with Quartz Vein (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Jasper with Quartz Vein

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Sandy Ironstone (Ferruginous Sandstone) — sedimentary

Sandy Ironstone

Ferruginous Sandstone

Septarian Nodule (Dragon Stone) (Septarian concretion (composition: CaCO3 - Calcite, Aragonite, and Siderite/Limestone)) — sedimentary

Septarian Nodule (Dragon Stone)

Septarian concretion (composition: CaCO3 - Calcite, Aragonite, and Siderite/Limestone)

Yellow Jasper (Iron-stained Chert) (Silicon Dioxide (SiO2) with iron oxide (Limonite/Goethite) inclusions) — sedimentary

Yellow Jasper (Iron-stained Chert)

Silicon Dioxide (SiO2) with iron oxide (Limonite/Goethite) inclusions

Jasper (Iron-stained Chert) (Silicon Dioxide (SiO2) with impurities of Hematite or Goethite) — sedimentary

Jasper (Iron-stained Chert)

Silicon Dioxide (SiO2) with impurities of Hematite or Goethite

Amethyst Sage Agate (Silicon Dioxide (SiO2) with trace minerals (Manganese/Iron oxides)) — mineral

Amethyst Sage Agate

Silicon Dioxide (SiO2) with trace minerals (Manganese/Iron oxides)