Quartz
Silicon Dioxide (SiO₂)
Category
Browse sedimentary (chemically precipitated) or metamorphic specimens identified by the Rock Identifier community.
Quartz
Silicon Dioxide (SiO₂)
Satin Spar (Selenite)
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
Red Jasper
Jasper (SiO2, Silicon Dioxide with Iron inclusions)
Yellow Jasper
Silicon dioxide (SiO2)
Geode (Unbroken)
Silicon Dioxide (SiO2) usually as Microcrystalline Quartz or Chalcedony
Quartz Geode
Quartz (Silicon Dioxide, SiO2) Geode
Ironstone Concretion (Moqui Marble)
Iron Oxide Concretion (Fe2O3 / FeO(OH) mixed with SiO2)
Travertine (Tufa)
Chemical Sedimentary Limestone (CaCO3)
Limonite (often after Hematite or Goethite)
Limonite (FeO(OH)·nH2O)
Ferruginous Sandstone
Sandstone (arenite) with Limonite/Goethite cement
Geode with Quartz Crystal Cavity
Silicon Dioxide (SiO2) in Calcareous/Siliceous Matrix
Quartz (vein quartz)
SiO2 (Silicon Dioxide)
Quartzite
Quartzite
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily SiO2 with Fe2O3 staining)
Chert (or Flint)
SiO2 (predominantly microcrystalline quartz)
Druzy Quartz
Silicon Dioxide (SiO2)
Quartz
Quartz (SiO₂ - Silicon Dioxide)
Chert (Grey/Black variety)
Chert (Silicon Dioxide, SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (Iron-stained)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Red Chert (Jasper)
Cryptocrystalline Quartz (SiO2) with iron oxide inclusions
Amethyst
Quartz (Silicon Dioxide, SiO2) with iron impurities
Bumblebee Jasper
Calcite-bearing Volcanic Tuff containing Sulfur and Arsenic (Orpiment/Realgar)
Fossilized Dinosaur Skull (Tyrannosaurus rex)
Tyrannosaurus rex (permineralized fossil), rich in Hydroxylapatite/Silica
Ironstone Concretion (Moqui Marble)
Ironstone concretion (Fe2O3 with a sandstone core)
Muscovite Mica (in Quartz matrix)
Potassium aluminum silicate hydroxide fluoride (KAl2(AlSi3O10)(F,OH)2)
Epidote (or Epidote-rich rock)
Epidote. Mineral formula: Ca2(Al,Fe)3(SiO4)3(OH).
Chalcedony (variations like Agate or Jasper)
Chalcedony (SiO₂ - microcrystalline quartz)
Banded Iron Formation (Jaspilite)
Banded Iron Formation (BIF); predominantly Hematite (Fe2O3) and Magnetite (Fe3O4) with Chert/Jasper (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Breciated Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
Quartzite
Quartzite (SiO2)
Green Quartzite
Quartzite (primarily SiO2 with trace impurities)
Botryoidal Chalcedony
Chalcedony (SiO2)
Quartzite
Quartzite (Primary mineral: SiO2)
Quartzite (River Cobble)
SiO2 (Quartz-rich Metamorphic Rock)
Jasper (Red Jasper)
Jasper (SiO2 - Silicon Dioxide with iron inclusions)
Quartz Geode
Silicon Dioxide (SiO2)
Jasper (specifically Yellow/Red Jasper)
Silicon Dioxide (SiO2) with iron oxide inclusions
Green Jasper
Silicon Dioxide (SiO2) with impurities
Amethyst or Smoky Quartz Geode Slice
Crystalline Silicon Dioxide (SiO2) with iron impurities
Iron-stained Quartz (with Limonite/Hematite)
Silicon Dioxide (SiO2) with Iron Oxide inclusions (FeO(OH) or Fe2O3)