Chert (Flint Nodules)
Silicon Dioxide (SiO2)
Category
Browse organic (mineraloid) specimens identified by the Rock Identifier community.
Chert (Flint Nodules)
Silicon Dioxide (SiO2)
Fossiliferous Limestone
Limestone with embedded fossil cross-section
Chert (Flint)
Silicon Dioxide (SiO2)
Chert / Flint
Chert (SiO2)
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Chert (Arrowhead Preform or Point)
Chert (Microcrystalline Quartz, SiO2)
Shungite
Non-crystalline carbon (allotrope of carbon)
Jasper
Jasper (Silicon Dioxide, SiO2)
Amber
Succinite (amorphous organic polymer)
Rough Amber (likely Copal or immature Amber)
Organic gemstone / Succinite (if Baltic)
Amber
Amber (Amorphous Organic Hydrocarbon)
Amber
Succinite (a fossilized organic resin)
Coal (most likely Bituminous or Anthracite)
Coal (organic sedimentary rock)
Dendritic Agate
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
Amber
Succinite (fossilized resin)
Tree Agate (also known as Dendritic Agate)
Silicon Dioxide with inclusions (SiO2 + Mn/Fe)
Banded Chert
Sedimentary Cryptocrystalline Quartz (SiO2)
Red Coral (Precious Coral)
Corallium rubrum (Calcium Carbonate, CaCO3)
Glauconite (Greensand)
(K, Na)(Fe3⁰, Al, Mg)₂(Si, Al)₄O₁₀(OH)₂
Black Pearl (Tahitian Type)
Aragonite / Pinctada margaritifera (CaCO3 + Conchiolin)
Dendritic Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with inclusions
Quartz River Pebble with Algae
Silicon Dioxide (SiO2) with organic biofilm
Baroque Pearl
Biogenic Calcium Carbonate (Aragonite/Conchiolin)
Amber
Succinite (Resin C10H16O)
Zebra Rock / Zebra Marble
Banded Limestone-Marble Transition
Amber
Succinite (fossilized resin)
Amber
Succinite
Nacre (Mother of Pearl)
Nacre (Biogenic Aragonite/Calcite composite, CaCO3)
Petrified Wood
Silicified Wood (SiO2)
Pyritized Ammonite
Ammonitida (replaced by Iron Disulfide, FeS2)
Chert (Jasper)
Silicon dioxide (SiO2)
Chert (Jasper variety)
Microcrystalline Quartz (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Bamboo Leaf Jasper
Silicified Siltstone or Jasper (SiO2)
Shungite
Non-crystalline carbon (Fullerenes)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Pearl (likely Freshwater or Akoya Cultured)
Aragonite / Conchiolin composite (CaCO3)
Fossil Crab
Decapoda (likely Avitelmessus or Raninidae family)
Shale with Coprolite influence
Argillaceous sedimentary rock (Shale/Mudstone)
Sandstone Concretion with Fossil Wood
Ferruginous Sandstone Concretion (SiO2 with Fe2O3 cement)
Dendritic Limestone
Calcite with Manganese Oxide (Manganese Dendrites)
Coquina or Fossiliferous Limestone
Fossiliferous Calcarenite (CaCO3)