Petrified Wood
Silicified Wood (SiO2)
Category
Browse organic (pseudo geological) specimens identified by the Rock Identifier community.
Petrified Wood
Silicified Wood (SiO2)
Fossilized coral (likely honeycomb or branching coral)
Fossil coral; probable Scleractinia or Tabulata, composition mainly microcrystalline CaCO₃
Moss Agate
Silicon Dioxide (SiO2) with inclusions of manganese or iron oxides
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide and organic impurities
Shale (with minor calcite veining)
Clastic sedimentary rock (primarily clay minerals and quartz)
Chert (Cherty Shale / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert Nodule
Microcrystalline Quartz (SiO2)
Iron Ore / Hematite / Ironstone Nodule
Hematite / Goethite (Fe2O3 / FeO(OH))
Septarian Nodule or Mud Crack Fossil
Septarian Nodule (Concretion)
Green Moss Agate
Agate (Silicon Dioxide - SiO2) with inclusions of hornblende or chlorite
Chert Nodule in Limestone (Flint in Chalk)
SiO2 (Microcrystalline Quartz) in CaCO3 (Calcite)
Banded sandstone pebble
Lithified quartz–feldspar sandstone, likely ferruginous and carbonaceous laminae
Grey and White Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Jasper (Red-Brown)
Silicon Dioxide (SiO2) with Iron Oxide impurities
Chert (Quartz Variety)
Microcrystalline Silica (SiO2)
Chert (specifically Tan/Yellow Chert)
Chert (Microcrystalline or Cryptocrystalline Silica, SiO2)
Red Jasper
Red Jasper (variety of Chalcedony, SiO₂)
Chert Nodule
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Fossil Brachiopod
Phylum Brachiopoda
Petrified Wood
Silicified Wood (primarily SiO2)
Weathered gray-green rock fragment
Likely shale or mudstone; exact identification requires testing
Silty Shale or Mudstone
Siltstone/Mudstone (Clastic Sedimentary Rock)
Petrified Wood
Silicified Wood (primarily SiO2)
Fossil Coral
Phylum Cnidaria / Rugosa or Tabulata
Weathered shale or mudstone
Clastic mudrock, chiefly clay minerals, quartz, and feldspar
Tumbled chert or flint
Microcrystalline quartz (SiO₂), likely brown chert/flint
Chalk
Calcium Carbonate (CaCO3)
Petrified Wood
Silicified Wood (SiO2)
Chert / River Jasper
Microcrystalline Quartz (SiO2)
Moqui Marble (Shaman Stone)
Iron Oxide Concretion (composed primarily of Quartz sand with Hematite/Goethite shell)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (with Quartz Veining)
Chert (formula: SiO2)
Limestone (Concretionary or Tufa)
Calcium Carbonate (CaCO3)
Petrified Wood
Silicified Wood (SiO2)
Biological Bone (Patella/Knee)
Patella (part of the Human Skeletal System)
Moss Agate
Cryptocrystalline Quartz (SiO2 with Manganese or Iron Oxide inclusions)
Petrified Wood
Petrified Wood (Silicified Wood)
Petrified Wood
Silicified Wood (SiO2)
Shale
Shale (fine-grained clastic sedimentary rock)
Graphite-rich schist (probable graphite flake)
Graphite (C) in graphitic schist; possibly graphite-bearing phyllite