Petrified Wood
Silicified Wood (SiO2)
Category
Browse organic (often found by beachcombers) specimens identified by the Rock Identifier community.
Petrified Wood
Silicified Wood (SiO2)
Green Chert
Microcrystalline Quartz (SiO2)
Chert (White Chert/Flint)
Chert (SiO2)
Petrified Wood
Silicon Dioxide (SiO2) permineralized organic matter
Chert (Jasper variation)
Microcrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline silicon dioxide (SiO2)
Chert Arrowhead (Projectile Point)
Microcrystalline Quartz (SiO2)
Bituminous Coal
Bituminous coal (Organic Sedimentary Rock)
Crinoid Fossil in Limestone
Crinoid (Class Crinoidea) in Fossiliferous Limestone (CaCO3)
Chert (Chalky variety)
Microcrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Chert (often called Flint)
Silicon Dioxide (SiO2)
Amber
Succinicum (C10H16O)
Chert (specifically Flint or Common Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Tree Agate
Silicon Dioxide (SiO2) with Dendritic Inclusions
Chert (Nodule)
Silicon Dioxide (SiO2)
Chert (Light Grey / Flint variant)
Cryptocrystalline Quartz (SiO2)
Shale (or Mudstone)
Siltstone/Argillite (composed mainly of clay and silt-sized particles)
Pink Opal
Amorphous Hydrous Silica (SiO2·nH2O)
Chert (Jasper type)
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Moss Agate
Cryptocrystalline Quartz (SiO2 with Manganese or Iron Oxide inclusions)
Chert (River Pebble)
Microcrystalline Quartz (SiO2)
Graphite
Graphite (C)
Banded Chert (Jasper)
Silicon Dioxide (SiO2)
Chert (Pink variety/Jasper)
Silicon Dioxide (SiO2)
Chert (variations include Flint)
Chert (Silicon Dioxide, SiO2)
Shale (with minor calcite veining)
Clastic sedimentary rock (primarily clay minerals and quartz)
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Black Chert or Flint)
Silicon Dioxide (SiO2)
Chert (Iron-Stained)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Chert (specifically Tan Chert or Flint)
Silicon Dioxide (SiO2)
Dinosaur Fossil (Skull)
Dinosauria fossilis (Petrified Hydroxyapatite / Calcium Carbonate)
Moss Agate and Hematite
Silica (SiO2) with fibrous inclusions of Manganese or Iron; Hematite (Fe2O3)
Chert (specifically Gray/Black Chert)
Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)
Coal (most likely Bituminous or Anthracite)
Coal (organic sedimentary rock)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Yellow Chert
Sedimentary cryptocrystalline quartz (SiO2)
Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
Travertine
Calcareous Tufa / Travertine (CaCO3)
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, SiO2)