Petrified Wood
Silicified Wood (SiO2 permineralization)
Category
Browse organic (paper and cellulose) specimens identified by the Rock Identifier community.
Petrified Wood
Silicified Wood (SiO2 permineralization)
Petrified Wood
Silicified wood (primarily SiO2 - Silicon Dioxide/Quartz)
White seed-bead gemstone strand, likely freshwater pearl or shell pearl
Pearl: nacreous calcium carbonate, chiefly aragonite (CaCO₃) in conchiolin; identification uncertain from image
Baltic Amber (Butterscotch or Egg Yolk Variety)
Succinite (chemical formula: C10H16O)
Honey Calcite
Calcium Carbonate (CaCO3)
Tufa (Limestone)
Calcareous Tufa (CaCO3)
Moss Agate
Silicon Dioxide with inclusions (SiO2)
Moss Agate
Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxide
Jasper (Green/Yellow Moss Jasper)
Silicon Dioxide (SiO2)
Moss Agate
Chalcedony (SiO2) with inclusions of manganese or iron oxides
Amber
Succinite (fossilized resin)
Iron-stained quartz-rich rock, possibly jasper or chert
Microcrystalline quartz (SiO₂) with iron oxides/hydroxides
Ironstone Concretion (Ironstone Gourd)
Limonite/Goethite Concretion (FeOO(H))
Amber
Succinite (a fossilized organic resin containing succinic acid)
Moss Agate
Silicon Dioxide with inclusions (SiO2 + impurities)
Amber
Succinite (with empirical formula approximately C10H16O)
Fossil gastropod shell
Fossilized marine gastropod; exact genus/species requires locality and examination
Black Marble
Recrystallized Calcite (CaCO3)
Slate
Slate (Foliated metamorphic rock)
Ferruginous Sandstone (Ironstone)
Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)
Orange Calcite
Calcium Carbonate (CaCO3)
Petrified Wood
Silicified Wood (SiO2)
Chert (with Quartz vein)
Chert (Silicon Dioxide, SiO2)
Tumbled amber-like inclusion
Likely amber (fossilized tree resin; complex polymer), but identification is uncertain from the image
Coquina
Biogenic Limestone (Calcium Carbonate - CaCO3)
River Rock
Silica-rich water-worn rock
Amber with dark mineral/organic inclusions
Fossilized plant resin (amber; chiefly polymerized diterpenoid resin)
Petrified Wood
Silicified Wood (SiO2 permineralization)
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Chert (Flint / Jasper / Hornstone)
Microcrystalline Quartz (SiO2)
Shale with Plant Fossils / Carbonaceous Shale
Laminated Mudrock (Siliciclastic)
Blue Agate (Tumbled and Dyed)
Silicon Dioxide (SiO2) with likely organic dyes
Glauconitic Sandstone
Glauconitic Quartz-Wacke / Sandstone (Fe(II),Fe(III),Al,Mg)2-3(Si,Al)4O10(OH)2
Fossil Shell (Bivalve)
Class Bivalvia (Likely a member of the Ostreidae or Gryphaeidae family), CaCO3
Bituminous Coal
Bituminous coal (Organic Sedimentary Rock)
Septarian Nodule (Polished)
Septarian concretion (Calcite, Aragonite, Limestone)
Fossilized Shark Tooth
Chondrichthyes (Class)
Chert (Iron-stained)
Silicon Dioxide (SiO2) with Iron Oxides
Petrified Wood
Silicified Wood (primarily quartz/chalcedony replacing organic wood structure)
Petrified Wood
Silicified wood (Quartz replacement)
Coal
Bituminous Coal (organic sedimentary rock)