Chert with Fossil Brachiopod
Microcrystalline Quartz (SiO2) with Calcitic Brachiopod inclusion
sedimentary
Category
Organic Gemstone (Not A Rock)
Browse organic gemstone (not a rock) specimens identified by the Rock Identifier community.
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Chert (Flint)
Microcrystalline Silicon Dioxide (SiO2)
sedimentary
Chert Arrowhead (Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Jasper variety)
Silicon Dioxide (SiO2)
sedimentary
Baltic Amber
Succinite (Fossilized Resin)
fossil
White seed-bead gemstone strand, likely freshwater pearl or shell pearl
Pearl: nacreous calcium carbonate, chiefly aragonite (CaCO₃) in conchiolin; identification uncertain from image
gemstone
Biological Bone (Patella/Knee)
Patella (part of the Human Skeletal System)
Organic Structure (Not a Rock)
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Chert (River Pebble)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Ironstone Concretion (Moqui Marble / Boji Stone)
Sedimentary Iron Oxide Concretion (Fe2O3 / FeO(OH))
sedimentary
Bituminous Coal
Organic Sedimentary Rock (Carbon-based)
sedimentary
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Shale
Mudstone (composed primarily of clay minerals like kaolinite, illite, and smectite, with quartz and calcite)
sedimentary
Amber
Succinite (C10H16O)
gemstone
Sandstone (River Cobble)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Chalcedony (Common Agate)
Silicon Dioxide (SiO2)
mineral
Amber
Succinite (Fossilized Tree Resin)
fossil
Black Freshwater Pearls
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
mineral
Chert Concretion / Nodule
Microcrystalline Quartz (SiO2)
sedimentary
Coal (Anthracite / Bituminous)
Organic Sedimentary Rock (Carbon-based)
sedimentary
Coal
Bituminous Coal (organic sedimentary rock)
sedimentary
Bituminous Coal
Bituminous coal (Organic Sedimentary Rock)
sedimentary
Bituminous Coal
Organic Sedimentary Rock (Carbon-based)
sedimentary
Amber
Succinite (approximate formula C10H16O)
mineral
Black Limestone with Calcite Veins
Limestone (Calcium Carbonate, CaCO3)
sedimentary
Amber
Succinite (C10H16O)
mineral
Pearl (likely Freshwater or Akoya Cultured)
Aragonite / Conchiolin composite (CaCO3)
Mineralloid (Organic gemstone)
Concrete or asphalt-like aggregate surface with a dark fragment
Uncertain; likely artificial concrete containing mixed lithic aggregate, not a natural rock
sedimentary
Chert (Jasper)
Silicon Dioxide (SiO2)
sedimentary
Amber
Succinite (approximate formula C10H16O)
mineral
Chert / Flint
Silicon Dioxide (SiO2)
sedimentary
Chert (often called Flint when found in chalk)
Microcrystalline Quartz (SiO2)
sedimentary
Note: Item is not a geological specimen
n/a
none
Jasper
Silicon Dioxide (SiO2)
sedimentary
Chert (Yellow Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Chert Nodules in Sedimentary Rock
Microcrystalline Quartz (SiO2) within Clastic Matrix
sedimentary
Sandstone
Arenite
sedimentary
Chert (Jaspery variety)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (White Chert/Flint)
Silicon Dioxide (SiO2)
sedimentary
Fossiliferous Limestone
Biogenic Limestone with Brachiopod/Crinoid fragments
sedimentary
Chert (often called Flint)
Chert (Microcrystalline or cryptocrystalline Silica, SiO2)
sedimentary