Petrified Wood
Silicified Wood (SiO2)
Category
Browse organic (non geological) specimens identified by the Rock Identifier community.
Petrified Wood
Silicified Wood (SiO2)
Chert (Pink Jasper)
Microcrystalline Quartz (SiO2)
Quartzite
Quartzite (primarily SiO2)
Obsidian
Volcanic glass (mainly SiO2)
Obsidian
Obsidian (Volcanic Glass)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Obsidian
Obsidian (volcanic glass), amorphous SiO2 + impurities
Grey Quartzite Pebble
Quartzite (primarily SiO2 - Silicon Dioxide)
Ironstone Concretion / Limonite Node
Goethite and Limonite (FeO(OH) nH2O)
Slag Glass
Anthropogenic Amorphous Silicon Dioxide
Fossilized Fish Skeleton in Matrix
Vertebrata (Class: Actinopterygii), typically found in limestone or shale matrices
Geode with Quartz Crystal Cavity
Silicon Dioxide (SiO2) in Calcareous/Siliceous Matrix
Glauconitic Sandstone (Greensand)
Glauconitic quartz wacke or arenite
Anthracite Coal
Anthracite (Carbon Content: 86%-97%)
Petrified Wood
Silicified Wood (SiO2)
Glauconitic Sandstone
Glauconitic Quartz Arenite
Obsidian (Black Obsidian)
Obsidian (Volcanic Glass)
Obsidian
Obsidian (Extrusive Volcanic Glass)
Sandstone Concretion
Arenaceous concretion (primarily SiO2 with Fe2O3 staining)
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Green Calcite
Calcium Carbonate (CaCO3)
Apache Tear (Obsidian)
Obsidian / Amorphous Volcanic Glass (primarily SiO2)
Quartzite
Quartzite (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (SiO2 - Silicon Dioxide)
Black Jasper
Black Jasper (Silicate mineral - SiO2)
Siltstone
Siltstone
Common Opal (Green Opal / Pistachio Opal)
Hydrated silica (SiO2·nH2O)
Chert (and/or Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (specifically Yellow/Brown Chert or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Red Jasper variant)
Microcrystalline Quartz (SiO2)
Sandstone
Arenite (primarily composed of SiO2)
Chert (variant Flint)
Silicon Dioxide (SiO2)
Chert (Flint variety)
Chert (Microcrystalline or Cryptocrystalline Quartz), SiO2
Siltstone with Quartz Vein
Siltstone (primarily SiO2, Al2O3, Fe2O3)
Biotite Mica in Host Rock
Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)
Petrified Wood
Silicified Wood (SiO2)
Slag Glass (Cullet Glass)
Amorphous Silica (Industrial byproduct)
Obsidian with Spherulitic Devitrification (Snowflake Obsidian/Mahogany related)
Volcanic Glass (70% or more SiO2)
Wonderstone (Liesegang Sandstone)
Silicified Sandstone with Liesegang Rings (SiO2 + FeO(OH))
Chert (specifically Flint or Jasper variant)
Microcrystalline Quartz (SiO2)