Petrified Wood
Silicified Wood (SiO2)
Category
Browse organic materia (not a rock or mineral) specimens identified by the Rock Identifier community.
Petrified Wood
Silicified Wood (SiO2)
Moss Agate
Agate (Silicon Dioxide, SiO2) with dendritic inclusions
Amber (Rough Baltics/Beach Specimen)
Succinicum (Organic Gemstone - Fossilized Resin)
Sandstone
Arenite (primarily composed of SiO2)
Moss Agate
Chalcedony (SiO2) with dendritic inclusions of Manganese or Iron oxide
Moss Agate
Silicon Dioxide with inclusions (SiO2 + Fe/Mn/Mg)
Chert (concretionary/nodular variant)
Microcrystalline Quartz (SiO2) with possible fossil or mineral inclusions
Sandstone Pebble
Arenite (primarily SiO2)
Moss Agate
Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxide
Chert Nodule
Microcrystalline Silica (SiO2)
Chert (Septarian or Nodular variety)
Microcrystalline Quartz (SiO2)
Tree Agate
Dendritic Agate (Silicon Dioxide, SiO2)
Shale with Pyrite
Clastic sedimentary rock containing Iron Disulfide (FeS2)
Shungite
Shungite (carbon-rich Precambrian rock)
Yellow Chert (Jasper)
Silicon Dioxide (SiO2)
Sandstone Chert Concretion
Silica-cemented Concretion (primarily SiO2)
Fossilized Coral
Cnidaria (Anthozoa), often replaced by Calcium Carbonate (CaCO3) or Silica (SiO2)
Chert with Quartz/Calcite Vein
Microcrystalline Silica (SiO2)
Petrified Wood
Silicified Wood (primarily SiO₂ / Silicon Dioxide)
Sandstone (Weathered Coastal Boulder)
Arenite (composed primarily of SiO2)
Chert (Jasper/Flint Pebble)
Microcrystalline quartz (SiO2)
Dendritic Agate
Chalcedony (SiO2) with manganese/iron oxide inclusions
Turquoise and Red Coral
Turquoise: CuAl6(PO4)4(OH)8·4H2O; Red Coral: Corallium rubrum (organic gemstone)
Chert (Chert / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Brachiopod Fossil in Limestone
Phylum Brachiopoda (likely Order Spiriferida), CaCO3 (Calcite)
Chert (with Quartz Vein)
Chert (Siliceous sedimentary rock, predominantly Microcrystalline Quartz SiO2)
Fossilized Horn Coral
Order Rugosa (Rugose Coral)
Tufa (Limestone)
Calcareous Tufa (CaCO3)
Pink Opal
Amorphous Hydrous Silica (SiO2·nH2O)
Chert (Nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Sandstone (likely Fossilized Wood or Concrete Simulacrum)
Arenite / Silicified Wood / Anthropogenic Concrete
Shale (sub-type: Carbonaceous Shale)
Lutaceous Sedimentary Rock
Limestone with Quartz/Calcite Veins
Sedimentary Limestone (CaCO3 with SiO2 or CaCO3 intrusions)
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, formula: SiO2)
Shale
Fissile Clay-dominant Mudrock (SiO2, Al2O3, K2O, Na2O, CaO, MgO)
Moss Agate
Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxides
Chert with Quartz Veining
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
Chert (varietal: Flint/Jasper mix)
Hydrous Silica (SiO2)
Red Jasper
Silicon dioxide (SiO2) with iron oxide (Fe2O3) inclusions
Chert / River Pebble
Silicon Dioxide (SiO2)
Amber
Succinite (fossilized resin, C10H16O)