Obsidian
Volcanic Glass (70-75% SiO2 with MgO and Fe3O4)
Category
Browse biogenic material specimens identified by the Rock Identifier community.
Obsidian
Volcanic Glass (70-75% SiO2 with MgO and Fe3O4)
Chert (specifically Jasper/Flint)
Microcrystalline Quartz (SiO2)
Chert / Flint
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (variations include Flint or Jasper)
Chert (Silicon Dioxide, SiO2)
Chert (often called Flint or Jasper)
Silicon Dioxide (SiO2)
Chert (Chalcedony)
Microcrystalline Quartz (SiO2)
Smoky Quartz with Feldspar
Silicon Dioxide (SiO2) with Potassium Feldspar (KAlSi3O8)
Chert (Iron-stained variant)
Microcrystalline Quartz (SiO2)
Ferruginous Quartz
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
Chert (Chert / Flint)
Silicon Dioxide (SiO2)
Red Sandstone
Arenite (with Iron Oxide cement)
Chrysocolla
Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nHeO)
Zebra Marble
Metamorphosed Limestone (Recrystallized Calcite)
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
Ocean Jasper
Orbicular Jasper (Silicon Dioxide SiO2)
Fired Clay Brick (Anthropic Rock substitute)
Anthropogenic polycrystalline ceramic (predominantly Mullite and Quartz: Al6Si2O13 + SiO2)
Fossilized Shark Tooth
Chondrichthyes (Class) fossilized tooth
Red jasper / iron-rich chert
Microcrystalline quartz (SiO₂) colored by hematite/goethite
Olivine (Peridot)
(Mg,Fe)2SiO4
Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Calcite
Calcium Carbonate (CaCO3)
Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz Crystal Cluster
Silicon Dioxide (SiO2)
Yellow Calcite
Calcium Carbonate, CaCO3
Gray River Pebble (Limestone or Greywacke)
Sedimentary Pebble (Calcite / Quartz composition)
Clear Quartz (Faceted)
Silicon dioxide (SiO2)
Limestone (Carved Statue)
Calcium Carbonate (CaCO3)
Clear Quartz
Silicon Dioxide (SiO2)
Peridotite (Olivine Rock)
Peridotite (composed largely of olivine, (Mg, Fe)2SiO4)
Limestone with Gastropod Fossil
Sedimentary Calcium Carbonate (CaCO3) with Gastropoda inclusion
Bauxite
Bauxite (Mixture of Al(OH)3, AlO(OH), and Fe2O3)
Kyanite
Kyanite (Al2SiO5)
Planet Earth
Gaia (Silicate Terrestrial Planet)
Quartz (Small Fragment)
Silicon Dioxide (SiO2)
Bauxite
Bauxite (Al2O3·nH2O)
White seed-bead gemstone strand, likely freshwater pearl or shell pearl
Pearl: nacreous calcium carbonate, chiefly aragonite (CaCO₃) in conchiolin; identification uncertain from image