Obsidian
Obsidian (Volcanic Glass, SiO2)
Category
Browse organic (non geological) specimens identified by the Rock Identifier community.
Obsidian
Obsidian (Volcanic Glass, SiO2)
Shale
Shale (composition varies: primarily clay minerals and quartz)
Chert (containing Flint and Calcareous inclusions)
Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3) impurities
Limonite (Yellow Ochre)
Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)
Quartzite
Quartzite (Primary mineral: SiO2)
Rose Quartz
Silicon Dioxide with traces of titanium, iron, or manganese (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2) with Iron Oxide inclusions
Fossiliferous Limestone (Coquina)
Biogenic Limestone (Calcium Carbonate, CaCO3)
Pyrite
Iron Sulfide (FeS2)
Chert (Jasper/Flint variant)
Microcrystalline Quartz (SiO2)
Chert (often called Flint in this variation)
Silicon dioxide (SiO2) - Microcrystalline quartz
Chert (variations include Flint or Jasper)
Silicon Dioxide (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Pyrite in Shaly Matrix
Iron Sulfide (FeS2)
Grey Quartzite Pebble
Quartzite (primarily SiO2)
Obsidian (Apache Tear)
Volcanic Glass (Amorphous Silicon Dioxide, SiO2)
Black Obsidian
Obsidian (Volcanic glass), 70–75% SiO2
Black Obsidian
Obsidian (Volcanic Glass)
Obsidian
Amorphous volcanic glass (70-75% SiO2)
Obsidian
Amorphous volcanic glass (primarily SiO2)
Obsidian
Volcanic Glass (SiO2)
Chert (Brown Variety)
Microcrystalline quartz (SiO2)
Rough Green Beryl (Emerald variety)
Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)
Pyrite
Iron Sulfide (FeS2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Chert / Flint
Silicon Dioxide (SiO2)
Yellow Jasper / Chert
Jasper (Silica/Quartz) - SiO2
Chert (White Chert/Flint)
Chert (SiO2)
Fossil Shell (Bivalve)
Phylum Mollusca, Class Bivalvia (typically composed of Calcium Carbonate / CaCO3)
Chert (Jasper/Chalcedony variety)
Microcrystalline Quartz (SiO2)
Chert (White-Grey variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (specifically Flint or Common Chert)
Silicon Dioxide (SiO2)
Chert (variations include Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Fossil Coral (Rugosa or Solitary Coral)
Rugosa (Order), often referred to as 'Horn Coral' (Lithostrotionella or Grewingkia)
Agatized Fossil (Druzy Agate)
Silicon Dioxide (SiO2) replacing organic matter
Petrified Wood
Silicified Wood (primarily SiO2)
Obsidian
Volcanic glass (primary composition: SiO2)
Bull Quartz
Quartz (Silicon Dioxide - SiO2)
Quartzite
Quartzite (SiO2)