Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Category
Browse sedimentary (silica rich mineral variety) specimens identified by the Rock Identifier community.
Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Barite (Desert Rose or Cockscomb variety)
Barium Sulfate (BaSO4)
Orthoclase Feldspar (Salmon variety)
Orthoclase, KAlSi3O8
Quartz (Pale Rose or Milky Variety)
Silicon Dioxide (SiO2)
Chert (or Flint)
Chert (Sedimentary Cryptocrystalline Sio2)
Conglomerate
Conglomerate rock
Chert (Yellow Jasper/Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (with Iron Staining)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Calcite
Calcite (Calcium Carbonate, CaCO3)
Opaline Glass (Opalite)
Synthetic Silicon Dioxide Glass
Tiger's Eye
SiO2 (Quartz with inclusion of iron oxides)
Sandstone (Quartzose)
Arenite (SiO2 principal)
Limonite (Ironstone Concretion)
Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)
Chert (Flint)
Silicon Dioxide (SiO2)
Banded Chert (with Quartz Vein)
Microcrystalline Silica (SiO2)
Massive Cryptocrystalline Quartz (Chert/Chalcedony Pebble)
Silicon Dioxide (SiO2)
Rainbow Moonstone with Black Tourmaline
White Labradorite with Schorl (Na,Ca)(Al,Si)4O8
Milky Quartz
Silicon Dioxide (SiO2)
Orthoclase Feldspar (or K-Feldspar)
Orthoclase (KAlSi3O8)
Pink Halite (Himalayan Salt)
Halite (Sodium Chloride, NaCl)
Opal
Hydrous silicon dioxide (SiO2·nH2O)
Sandstone (Pebble)
Sandstone (arenite, arkose, wacke depending on composition)
Red Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
Red Jasper
Silicon dioxide (SiO2) with iron oxide (Fe2O3) inclusions
Petrified Wood
Silicified Wood (SiO2 as Quartz/Chert/Chalcedony)
Jasper with Quartz Veining
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Green Jasper
Silicon Dioxide (SiO2) with impurities
Chert (specifically Flint or Jasper variant)
Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)
Conglomerate
Conglomerate (SiO2 matrix with various silicate clasts)
Red Granite
Phaneritic Plutonic Felsic Rock (rich in Potassium Feldspar)
Carnelian (Red Chalcedony)
Silicon Dioxide (SiO2)
Carnelian
Carnelian (subset of Chalcedony); SiO2 with Iron Oxide impurities
Quartz Druze (on Matrix)
Silicon Dioxide (SiO2)
Chert (Flint Nodules)
Microcrystalline Quartz (SiO2)
Sandstone (Pebble/Conglomerate fragment)
Sandstone (clastic sedimentary rock)
Pyrite
Iron Sulfide (FeS2)
Pink Chalcedony
Silicon Dioxide (SiO2)
Jasper
Silicon dioxide (SiO2)
Sandstone (Wonderstone)
Arenite (composed primarily of SiO2 with Fe2O3 impurities)
Ironstone Concretion (Limonite/Hematite Nodules)
Ironstone (principally Limonite FeO(OH)·nH2O or Hematite Fe2O3 mixed with silica/clay)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Chert (variations include Chalcedony and Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)