Petrified Wood
Silicified Wood (primarily Chalcedony or Quartz, SiO2)
Category
Browse organic (non rock) specimens identified by the Rock Identifier community.
Petrified Wood
Silicified Wood (primarily Chalcedony or Quartz, SiO2)
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Chert (Field Stone)
Microcrystalline / Cryptocrystalline Quartz (SiO2)
Fossilized Coprolite
Coprolite (fossilized feces)
Diabase (Wormstone or Pebble)
Diabase (Dolerite)
Green Moss Agate
Silicon Dioxide (SiO2) with Mineral Inclusions
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Red Jasper
Jasper (Silicon Dioxide, SiO2)
Banded Chert (River Siltstone)
Microcrystalline Quartz (SiO2)
Chert (Arrowhead/Artifact Fragment)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert Pebble
Microcrystalline or cryptocrystalline Quartz (SiO2)
Quartzite River Cobble
Quartzite (SiO2)
Moss Agate
Chalcedony (SiO2) with inclusions of hornblende or chlorite
Anthracite Coal
Anthracite (Carbon-based sedimentary rock typically classified as metamorphic)
Moldavite
Tektite (Amorphous Silica, SiO2 + Al2O3)
Chert (Nodular)
Microcrystalline Silica (SiO2)
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
Flint (Chert)
Silicon Dioxide (SiO2)
Chert (often called Jasper or River Siltstone)
Microcrystalline Quartz (SiO2)
Chert (with Epidote/Quartz veining)
Cryptocrystalline silica (SiO2) with Epidote/Quartz inclusions
Travertine / Tufa
Calcium Carbonate (CaCO3)
Emerald in Matrix
Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities
Moss Agate
Chalcedony (Silicon Dioxide) with dendritic inclusions (SiO2)
Crinoid Fossil in Limestone
Crinoid (Class Crinoidea) in Fossiliferous Limestone (CaCO3)
Quartzite
Quartzite (primarily SiO2)
Limestone
Calcium Carbonate (CaCO3) / Limestone
Limestone Boulder
Sedimentary Rock (Calcium Carbonate, CaCO3)
Quartzite River Rock (with Limonite staining)
Quartzite (SiO2)
Travertine (Tufa)
Chemical Sedimentary Rock / Travertine (CaCO3)
Man-made Ceramic / Clay Figurine
Aluminosilicate Ceramic (Processed Clay)
Sandstone (Glauconitic)
Glauconitic Quartz Sandstone (SiO2 + (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert / Pink Flint
Cryptocrystalline Quartz (SiO2)
Chert (with Liesegang Banding)
Microcrystalline quartz (SiO2)
Sandstone (likely Fossilized Wood or Concrete Simulacrum)
Arenite / Silicified Wood / Anthropogenic Concrete
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 cement)
Serpentinite
Serpentinite (Mg, Fe, Ni)3Si2O5(OH)4
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Fossiliferous Limestone / Petrifaction
Sedimentary rock with fossil inclusions / Calcium Carbonate (CaCO3)
Chert (Jasper variation)
Silicon Dioxide (SiO2)
Chert with Quartz/Calcite Vein
Microcrystalline Silica (SiO2)
Shale (possibly Carbonaceous or Oil Shale)
Laminated Mudstone (primarily clay minerals and quartz)