Rock Identifier

Category

Organic (Geological Interest)

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

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Banded Chert (Microcrystalline silicon dioxide (SiO2)) — sedimentary

Banded Chert

Microcrystalline silicon dioxide (SiO2)

Amber (Succinite (specific to Baltic amber), fossilized tree resin) — mineraloid

Amber

Succinite (specific to Baltic amber), fossilized tree resin

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

Travertine (often colloquially called Tufa)

Chemical Sedimentary Calcium Carbonate (CaCO3)

Black Marble with Quartz Veining (Metamorphosed Limestone (Recrystallized CaCO3)) — metamorphic

Black Marble with Quartz Veining

Metamorphosed Limestone (Recrystallized CaCO3)

Moss Agate (Silicon Dioxide (SiO2) with inclusions of manganese or iron oxides) — Mineral (Variety of Chalcedony)

Moss Agate

Silicon Dioxide (SiO2) with inclusions of manganese or iron oxides

Mineral (Variety of Chalcedony)

Fossilized Gastropod (Snail) (Class Gastropoda (internal mold or 'steinkern')) — sedimentary

Fossilized Gastropod (Snail)

Class Gastropoda (internal mold or 'steinkern')

Sandstone (with carbonaceous plant fragments) (Arenite (composed primarily of SiO2)) — sedimentary

Sandstone (with carbonaceous plant fragments)

Arenite (composed primarily of SiO2)

Green Moss Agate (Silicon Dioxide (SiO2) with inclusions of hornblende or chlorite) — sedimentary

Green Moss Agate

Silicon Dioxide (SiO2) with inclusions of hornblende or chlorite

Shale or Slate with Quartz Veins (Shale (fine-grained clastic sedimentary rock) or Slate (low-grade metamorphic rock formed from shale) with Quartz (SiO2) veins) — Metamorphic, likely Sedimentary with Quartz veins

Shale or Slate with Quartz Veins

Shale (fine-grained clastic sedimentary rock) or Slate (low-grade metamorphic rock formed from shale) with Quartz (SiO2) veins

Metamorphic, likely Sedimentary with Quartz veins

Opalite (Synthetic Opalised Glass) — Mineral (Synthetic / Man-made)

Opalite

Synthetic Opalised Glass

Mineral (Synthetic / Man-made)

Graphite (Graphite (Carbon, C)) — Mineral

Graphite

Graphite (Carbon, C)

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

Basaltic Tuff / Volcanic Breccia

Pyroclastic Breccia / Lithic Tuff

Pyrite (Iron Pyrite (FeS2)) — mineral

Pyrite

Iron Pyrite (FeS2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

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

Quartz Geode

Silicon Dioxide (SiO2) within a secondary sedimentary structure

Quartz Geode (Silicon Dioxide (SiO2)) — sedimentary

Quartz Geode

Silicon Dioxide (SiO2)

Dendritic Opal (Common Opal) (Amorphous Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions) — mineral

Dendritic Opal (Common Opal)

Amorphous Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions

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)

Chert (with Quartz vein) (Chert (Silicon Dioxide, SiO2)) — sedimentary

Chert (with Quartz vein)

Chert (Silicon Dioxide, SiO2)

Zebra Marble (Metamorphosed Alabaster/Limestone (CaCO3)) — metamorphic

Zebra Marble

Metamorphosed Alabaster/Limestone (CaCO3)

Quartz (chalcedony variety) or Limestone with Quartz Veins (SiO2 (for Quartz/Chalcedony); CaCO3 (for Limestone)) — Mineral or Sedimentary Rock (with mineral inclusions)

Quartz (chalcedony variety) or Limestone with Quartz Veins

SiO2 (for Quartz/Chalcedony); CaCO3 (for Limestone)

Mineral or Sedimentary Rock (with mineral inclusions)

Wood Beads (Palmwood/Ebony) (Various species for wood, but often refers to woods like Palmwood (e.g., Borassus flabellifer) or Ebony (Diospyros spp.) for their distinctive grain and hardness.) — Organic Gem Material (Botanical)

Wood Beads (Palmwood/Ebony)

Various species for wood, but often refers to woods like Palmwood (e.g., Borassus flabellifer) or Ebony (Diospyros spp.) for their distinctive grain and hardness.

Organic Gem Material (Botanical)

Pyrite (Pyrite (Iron Disulfide), FeS2) — Mineral

Pyrite

Pyrite (Iron Disulfide), FeS2

Banded Chert / Banded Jasper (likely a variety of Chert/Chalcedony) (Chert (microcrystalline quartz)) — Metamorphic Rock

Banded Chert / Banded Jasper (likely a variety of Chert/Chalcedony)

Chert (microcrystalline quartz)

Metamorphic Rock

Ambergris (Physeter macrocephalus excreta (Ambergris)) — mineraloid / organic geological find

Ambergris

Physeter macrocephalus excreta (Ambergris)

mineraloid / organic geological find

Chert (Yellow Jasper variant) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Yellow Jasper variant)

Microcrystalline Quartz (SiO2)

Amber (Copal) (Organic gemstone, fossilized tree resin (often immature amber or copal)) — Mineral

Amber (Copal)

Organic gemstone, fossilized tree resin (often immature amber or copal)

Mother of Pearl (Nacre) (Calcium Carbonate (primarily aragonite, with conchiolin)) — Organic Gemstone/Biomineral

Mother of Pearl (Nacre)

Calcium Carbonate (primarily aragonite, with conchiolin)

Organic Gemstone/Biomineral

Graphite-veined Quartzite (Meta-sedimentary Quartzite with Carbonaceous/Graphitic Inclusions (SiO2 + C)) — metamorphic

Graphite-veined Quartzite

Meta-sedimentary Quartzite with Carbonaceous/Graphitic Inclusions (SiO2 + C)

Shale with Vein Infillings (Shale (a fine-grained clastic sedimentary rock). The veins could be Calcite (CaCO3), Quartz (SiO2), or other minerals.) — Sedimentary Rock

Shale with Vein Infillings

Shale (a fine-grained clastic sedimentary rock). The veins could be Calcite (CaCO3), Quartz (SiO2), or other minerals.

Sedimentary Rock

Shale (Shale (clastic sedimentary rock)) — Sedimentary

Shale

Shale (clastic sedimentary rock)

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

Petrified Wood

Silicified wood (primarily SiO2)

Red Jasper (beads) (SiO₂ (Silicon Dioxide)) — Mineral, variety of chalcedony (microcrystalline quartz)

Red Jasper (beads)

SiO₂ (Silicon Dioxide)

Mineral, variety of chalcedony (microcrystalline quartz)

Dendritic Agate (or Dendritic Opal) (SiO2 (for Agate), SiO2·nH2O (for Opal)) — Mineral

Dendritic Agate (or Dendritic Opal)

SiO2 (for Agate), SiO2·nH2O (for Opal)

Popcorn (Zea mays everta (P. Wilson) (Botanical name for the corn variety)) — Organic/Biogenic

Popcorn

Zea mays everta (P. Wilson) (Botanical name for the corn variety)

Organic/Biogenic

Pyrite (Pyrite (Iron Disulfide), FeS2) — Mineral

Pyrite

Pyrite (Iron Disulfide), FeS2

Brown Jasper (Likely) (Jasper (Cryptocrystalline Silicon Dioxide - SiO2)) — Mineral

Brown Jasper (Likely)

Jasper (Cryptocrystalline Silicon Dioxide - SiO2)

Chert (varietal: Jasper or Flint likely, but definitive identification is difficult from image) (SiO₂ (silicon dioxide)) — Sedimentary

Chert (varietal: Jasper or Flint likely, but definitive identification is difficult from image)

SiO₂ (silicon dioxide)

Banded Chert (Chert (a microcrystalline variety of quartz, SiO2 with minor impurities)) — Sedimentary

Banded Chert

Chert (a microcrystalline variety of quartz, SiO2 with minor impurities)

Chert / Flint (Chert (varietal name for microcrystalline quartz). Chemical formula: SiO₂) — Mineral

Chert / Flint

Chert (varietal name for microcrystalline quartz). Chemical formula: SiO₂