Petrified Wood (Agatized/Silicified Wood)
Silicified Wood / Chalcedony (SiO2)
Category
Browse organic (biological specimen) specimens identified by the Rock Identifier community.
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood / Chalcedony (SiO2)
Sandstone (Ferruginous)
Sandstone (SiO2 with iron oxide impurities)
Desert Varnish (on Sandstone)
Rock Varnish (composed of Manganese oxides, Iron oxides, and Clay minerals)
Flagstone paving (likely sandstone or limestone)
Clastic sandstone or carbonate limestone; exact identification requires testing
Banded sandstone pebble
Quartz-rich lithic sandstone; exact provenance and composition require testing
Green Jasper with Agate Banding
Silicon Dioxide (SiO2) with impurities of ferrous silicate or chlorite
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Fossilized Wood (with Coal and Limonite)
Petrified Wood (Silicified or Carbonized Flora)
Anthracite Coal
Anthracite (Carbon Content: 86%-97%)
Chert (likely Flint)
Cryptocrystalline Quartz (SiO2)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
Snowflake Obsidian
Volcanic glass containing Spherulite inclusions (primarily Cristobalite, SiO2)
Yellow Jasper
Silicon Dioxide (SiO2) with iron inclusions
Petrified Wood
Silicified Wood (primarily SiO₂ - Silicon Dioxide)
Fossiliferous limestone (likely ammonite/gastropod-bearing)
Bioclastic limestone; predominantly calcite (CaCO₃)
Chert with Calcite Veining
Microcrystalline Quartz (SiO2) with Calcium Carbonate (CaCO3) veins
Banded Agate (specifically Moss Agate or Plume Agate variety)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Arid Sandy Loam
Arenosols / Regosols
Hardpan Nodule / Ferruginous Sandstone
Ferruginous Sandstone (Fe-cemented sediment)
Fossil shark teeth
Probably fossilized shark teeth, possibly *Otodus* or *Carcharhinus* species
Dyed Coral
Calcium carbonate (CaCO3) - Calcite or Aragonite with dye
Amber (Copal)
Succinate (Fossilized Tree Resin)
Likely tumbled jasper or chert specimens
Microcrystalline quartz (SiO₂), commonly jasper/chert; exact identification is uncertain from the photograph
Graphite-veined Quartzite
Meta-sedimentary Quartzite with Carbonaceous/Graphitic Inclusions (SiO2 + C)
Moss Agate
Chalcedony (Silicon Dioxide with inclusions) - SiO2
Coquina
Biogenic Limestone (Calcium Carbonate, CaCO3)
Petrified Wood
Silicified wood (primarily Silicon Dioxide - SiO2)
Chert (Arrowhead or Projectile Point)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Septarian Nodule (Septarian Dragon Stone)
Septarian Concretion (Composition: Calcite, Aragonite, and Limestone/Clay)
Amber (Copal)
Fossilized Tree Resin
Chert (also known as Flint or Common Chalcedony)
Cryptocrystalline Silica (SiO2)
Moss Agate
Silicon Dioxide with inclusions (SiO2 + impurities)
Petrified Wood
Silicified wood (Quartz replacement, SiO2)
Amber and Citrine Quartz
Succinite (Amber) and Silicon Dioxide (SiO2 / Citrine)
Amber (Raw)
Succinite (Fossilized Resin)
Black Pearl (Tahitian Pearl)
Aragonite / Calcite (CaCO3) with Conchiolin
Amber
Succinite (fossilized resin, C10H16O)
Fossilized Bone
Vertebrate fossil (mineralized bone)
Chert (Agatized/Chalcedony variety)
Microcrystalline Quartz (SiO2)
Amber
Succinite (C10H16O)
Fluorite
Calcium Fluoride (CaF2)