Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
Category
Browse organic (non geological) specimens identified by the Rock Identifier community.
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
Chert (Brown Variety)
Silicon dioxide (SiO2)
Chert (and its variety Flint)
Silicon Dioxide (SiO2) - Microcrystalline or cryptocrystalline Quartz
Chert (variations include Flint or Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Coquina / Fossiliferous Limestone
Coquina (composed primarily of Calcium Carbonate / CaCO3)
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Chert / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Fluorite
Calcium Fluoride (CaF2)
Slag (Industrial Byproduct)
Anthropogenic Vitreous Silicate material
Fossiliferous Limestone
Fossiliferous Limestone (CaCO3 with organic inclusions)
Snowflake Obsidian
Volcanic glass containing Spherulites of Cristobalite (SiO2)
Honey Calcite
Calcium Carbonate (CaCO3)
Chert Nodule / Ironstone Concretion
Microcrystalline Quartz (SiO2) with Iron Oxides
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Obsidian
Volcanic Glass (Amorphous Silicon Dioxide)
Quartzite
Quartzite (SiO2)
Obsidian
Volcanic Glass (Extrusive Igneous Rock, primarily SiO2)
Black Obsidian with white veins
Volcanic Glass (70–75% SiO2)
Quartzite pebble
Quartzite (primarily SiO2)
Sandstone
Sandstone (Quartz-rich Arenite / SiO2)
Obsidian
Obsidian (Volcanic Glass, SiO2 > 70%)
Snowflake Obsidian
Volcanic Glass (SiO2 + impurities)
Siltstone with Quartz Vein
Siltstone (primarily SiO2, Al2O3, Fe2O3)
Obsidian
Volcanic Glass (mostly SiO2)
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement)
Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
Petrified Wood
Silicified Wood / Chalcedony (SiO2)
Sandstone Concretion
Arenaceous concretion (primarily SiO2 with Fe2O3 staining)
Quartzite
Quartzite (primarily SiO2)
Petrified Wood
Silicified Wood (SiO2)
Quartzite
Quartzite (SiO2)
Obsidian
Volcanic Glass (SiO2 with impurities)
Black Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Obsidian
Obsidian (Volcanic Glass), primarily SiO2
Biotite Mica in Host Rock
Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)
Quartzite
Metamorphic Quartzite (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Black Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Opalite
Man-made Synthetic Glass (Silicon Dioxide with metal additives)
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Obsidian
Volcanic Glass (SiO2)