Petrified Wood (Silicified Wood)
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
mineral
Category
Sedimentary (Fossilized Organic Remain)
Browse sedimentary (fossilized organic remain) specimens identified by the Rock Identifier community.
Petrified Wood
Silicified Wood (SiO2 - Silicon Dioxide)
mineral
Petrified Wood
Silicified Wood (SiO2 - Silicon Dioxide)
mineral
Anthracite Coal
Anthracite (Carbon-based organic sedimentary rock exposed to metamorphic heat/pressure; Chemical composition is approximately 86%–98% Carbon)
metamorphic
Sandstone
Arenite (primarily SiO2)
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Shale
Fissile Mudstone (primarily composed of phyllosilicate minerals like kaolinite, montmorillonite, and illite)
sedimentary
Wood Beads (Palmwood/Ebony)
Various species for wood, but often refers to woods like Palmwood (e.g., Borassus flabellifer) or Ebony (Diospyros spp.) for their distinctive grain and hardness.
Organic Gem Material (Botanical)
Pink Opal
Hydrated Silica (SiO2·nH2O) with Palygorskite inclusions
Mineraloid
Shale with Siltstone layering
Sedimentary Clastic Rock (Mudstone/Shale)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide / Chalcedony)
metamorphic
Sandstone (Quartz-rich)
Arenite (SiO2)
sedimentary
Carved Mottled Greenish-Yellow Crystal/Glass Object
Unknown; possibly a form of quartz (chalcedony/jadeite/nephrite) or glass/resin.
Man-made Object/Uncertain Mineral
Black Marble with Quartz Veining
Metamorphosed Limestone (Recrystallized CaCO3)
metamorphic
Sandstone (with man-made markings)
Arenite (composed primarily of Quartz, SiO2)
sedimentary
Shale (Beach-worn)
Laminated Pelite (primarily clay minerals and quartz)
sedimentary
Sandstone (Picture Sandstone)
Arenite (primarily SiO2)
sedimentary
Mudstone
Lutylite (group of fine-grained sedimentary rocks)
sedimentary
Baroque Pearl
Calcium Carbonate (Aragonite or Calcite) and Conchiolin
Organic Gemstone
Pearl (Cultured or Natural)
Aragonite (CaCO3) with Conchiolin
Organic Mineraloid
Popcorn
Zea mays everta (P. Wilson) (Botanical name for the corn variety)
Organic/Biogenic
Pearl (nacre)
Calcium Carbonate (mostly CaCO3 as Aragonite) and Conchiolin
Organic Mineraloid
Dog (Sleeping)
Canis familiaris (or Canis lupus familiaris)
Organic/Biological
Pearl (Imitation or Cultured)
Calcium Carbonate (Aragonite/Calcite) - CaCO3
Mineraloid (Organic)
Note: Item is not a geological specimen
Homo sapiens (Dermal Appendage: Pilus)
Organic / Biological
Ambergris
Ambrein (C30H52O Derivative)
Organic (Zoogenic)
Shungite
Carbonaceous rock (primarily amorphous carbon)
Mineraloid
Sandstone (Quartzite-rich)
Clastic sedimentary rock (SiO2 primary)
sedimentary
Sandstone
Arenite
sedimentary
Brown Sandstone
Arenite (primarily Quartz and Feldspar, with Iron Oxide cement)
sedimentary
Ferruginous Sandstone
Arenite with Iron-Oxide cement (Fe2O3 · nH2O)
sedimentary
Shale
Lutaceous sedimentary rock
sedimentary
Shale
Shale (Consolidated fine-grained clay/silt)
sedimentary
Chert (Flint variety)
Silicon Dioxide (SiO2)
sedimentary
Shale
Fissile mudstone (Shale)
sedimentary
Silty Shale
Silty Shale (Fissile Sedimentary Rock)
sedimentary
Sandstone
Clastic sedimentary rock (primarily SiO2)
sedimentary
Shale (Ferruginous)
Laminated Mudrock (Siliciclastic Sedimentary Rock)
sedimentary
Shale (with Iron Oxide staining)
Fissile Mudstone (primarily Quartz and Clay minerals)
sedimentary
Sedimentary Breccia
Breccia (Clastic Sedimentary Rock)
sedimentary
Sandstone
Clastic Sedimentary Rock (composed mostly of SiO2)
sedimentary
Shale
Fissile Siliciclastic Sedimentary Rock
sedimentary