Petrified Wood
Silicon Dioxide (SiO2) - Calcified / Silicified Wood
Category
Browse mineral (organic) specimens identified by the Rock Identifier community.
Petrified Wood
Silicon Dioxide (SiO2) - Calcified / Silicified Wood
Glauconitic Sandstone
Glauconitic Quartz Arenite
Dendritic Agate / Moss Agate
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
Precious Coral
Corallium rubrum (Calcium Carbonate, CaCO3)
Moss Agate
Silicon Dioxide (SiO2) with inclusions of hornblende or chlorite
Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with dendritic inclusions
Petrified Wood
Silicified Wood (primarily SiO2)
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, SiO2)
Honey Calcite
Calcium Carbonate (CaCO3)
Weathered fossilized wood (likely petrified wood)
Silicified wood; commonly quartz/chalcedony replacing wood tissue (SiO₂)
Amber
Fossilized Tree Resin (Generic formula roughly C10H16O)
Moss Agate
Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxide
Pearl
Organic gemstone (Calcium carbonate / CaCO3 + Conchiolin)
Moss Agate
Silicon Dioxide with inclusions (SiO2 + impurities)
Moss Agate
Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxide
Banded Agate (specifically Moss Agate or Plume Agate variety)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Petrified Wood
Silicified Wood (SiO2 as Quartz/Chert/Chalcedony)
Quartzite and Milky Quartz River Pebbles
Silicon Dioxide (SiO2)
Green Chert
Silicon Dioxide (SiO2)
Chert (specifically Flint or Jasper variant)
Microcrystalline Quartz (SiO2)
Chert (Jasper variety)
Silicon dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (Yellow Jasper)
Microcrystalline Quartz (SiO2)
Possible fossilized shell or coral fragment
Indeterminate biogenic carbonate, likely calcite (CaCO₃)
Petrified Wood
Silicified Wood (SiO2)
Chert (Flint Pebbles)
Microcrystalline Quartz (SiO2)
Chert (often called Flint or Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert / Flint
Silicon Dioxide (SiO2)
Chert (Green Chert)
Microcrystalline silica (SiO2)
Amber
Fossilized Tree Resin (C10H16O)
Ferruginous Sandstone (with possible trace fossils)
Arenite with Iron-Oxide Cement (SiO2 with Fe2O3)
Septarian Nodule
Septarian Nodule (Calcite, Aragonite, and Limestone/Claystone)
Turtle Stone / Septarian Nodule (Water-worn)
Septarian Concretion
Fossilized Shark Tooth
Chondrichthyes tooth
Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
Shale
Shale (Fine-grained clastic sedimentary rock)
Petrified Wood
Silicified Wood (Per mineral content: SiO2, Quartz/Chalcedony)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified wood (Quartz, SiO2)
Calcite crystal
Calcite (calcium carbonate, CaCO₃)
Amber
Succinite (C10H16O)
Pink Opal
Amorphous Hydrous Silica (SiO2·nH2O)