Banded Chert
Cryptocrystalline Quartz (SiO2)
Category
Browse organic (biological specimen) specimens identified by the Rock Identifier community.
Banded Chert
Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline silicon dioxide (SiO2)
Chert (Quartz Pebble)
Silicon Dioxide (SiO2)
Fossilized Bark
Lepidodendron / Sigillaria fossil impression
Petrified Wood
Silicified Wood (SiO2)
Orange Calcite
Calcium Carbonate (CaCO3)
Chert (and Limestone)
Silicon Dioxide (SiO2)
Pink Opal
Hydrated Silica (SiO2·nH2O)
Shale (with minor calcite veining)
Clastic sedimentary rock (primarily clay minerals and quartz)
Green Chert (Jasper)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Dendritic Agate
Silicon Dioxide with inclusions (SiO2 + Mn/Fe)
Chalcedony in Matrix (likely Agatized Coral or Chert)
Silicon Dioxide (SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2) with iron oxide impurities
Chert Pebble
Microcrystalline or cryptocrystalline Quartz (SiO2)
Pyrite
Iron Sulfide (FeS2)
Chert (Flint) Artifact
Silicon Dioxide (SiO2)
Chert (River Pebble)
Cryptocrystalline Quartz (SiO2)
Chert (with small quartz vug)
Chert (SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Chert (or Flint)
Chert (Sedimentary Cryptocrystalline Sio2)
Chert Pebble with Inclusion
Microcrystalline Quartz (SiO2)
Chert (specifically Flint or Jasper variant)
Microcrystalline Quartz (SiO2)
River Cobble (Sandstone)
Arenite (primarily SiO2)
Chert (often called Jasper or River Siltstone)
Microcrystalline Quartz (SiO2)
Ferruginous Sandstone Concretion (Ironstone Phosphorite)
Ferruginous Sandstone (variable Fe-oxide/hydroxide composition)
Concretionary Sandstone
Clastic Sedimentary Rock (Sandstone with secondary mineral cementation)
Chert (Jasper/Chalcedony)
Microcrystalline Quartz (SiO2)
Chert (Jasper/Agate variety)
Microcrystalline quartz (SiO2)
Chert (Nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Fossiliferous Limestone with Brachiopod
Limestone (Calcium Carbonate, CaCO3) with Phylum Brachiopoda fossil
Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with dendritic inclusions
Chert (Jasper variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (Brown variety)
Silicon Dioxide (SiO2)
Chert (specifically Pink/Tan Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Quartz Variety)
Silicon Dioxide (SiO2)
Chert (Jasper variation)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Petrified Wood
Silicon Dioxide (SiO2) permineralized organic matter
Petrified Wood
Silicified Wood (SiO2)
Fossil shark teeth
Likely fossilized shark teeth, possibly Carcharhiniformes or related sharks; exact species cannot be determined from the photo.
Chert (often called Flint when in chalk or limestone)
Silicon Dioxide (SiO₂)
Petrified Wood
Silicified Wood (SiO2)