Carnelian (Chalcedony)
Cryptocrystalline Quartz (SiO2) with Iron Oxide impurities
Category
Browse sedimentary rock (metamorphosed) specimens identified by the Rock Identifier community.
Carnelian (Chalcedony)
Cryptocrystalline Quartz (SiO2) with Iron Oxide impurities
Quartz Geode (partially formed/chalcedony with iron staining)
Quartz (SiO2) with Chalcedony (cryptocrystalline quartz) and likely Iron Oxides/Hydroxides
Travertine (used in construction, not a 'specimen' in situ)
Travertine
Sandstone (Red Sandstone / River Stone)
Arenite (composed primarily of Quartz, SiO2, with Iron Oxide cementation)
Quartz Druze (on Matrix)
Silicon Dioxide (SiO2)
Chert (or Flint)
Chert (Sedimentary Cryptocrystalline Sio2)
Banded Gneiss
Gneiss (Metamorphic high-grade rock)
Banded Gneiss
Gneiss (Metamorphic high-grade rock)
Orbicular Rhyolite (Rainforest Jasper)
Rhyolite containing Spherulites (SiO2 with impurities)
Green Adventurine
SiO2 (Silicon Dioxide with inclusions of Fuchsite mica)
Chert (specifically tan/pink variety)
Silicon Dioxide (SiO2)
Limonite (often after Hematite or Goethite)
Limonite (FeO(OH)·nH2O)
Quartz
Quartz (SiO₂ - Silicon Dioxide)
Ironstone Concretion (likely)
Goethite/Hematite/Limonite cemented sediment
Desert Rose
Gypsum (CaSO4·2H2O) or Baryte (BaSO4) with trapped sand grains
Carnelian Agate
Silicon Dioxide (SiO2) with Iron Oxide impurities
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Sandstone
Quartz Arenite (a common type of sandstone, given the appearance), Arkose, Greywacke (depending on mineralogy)
Wishing Stone (Basalt or Siltstone with Quartz/Calcite Vein)
Basalt (SiO2+MgO+FeO) or Siltstone with a Quartz (SiO2) or Calcite (CaCO3) vein
Gneiss (with Quartz and Biotite Mica)
Gneiss
Petrified Wood
Silicified Wood (SiO2)
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Siltstone with Quartz Vein
Siltstone (primarily SiO2, Al2O3, Fe2O3)
Chert (Pebble)
Microcrystalline silica (SiO2)
Chert (specifically a fragment with Desert Varnish)
Microcrystalline quartz (SiO2)
Coquina
Bioclastic Limestone
Fossiliferous Limestone (Coquina / Shell Conglomerate)
Bioclastic Limestone (composed primarily of CaCO3)
Oolitic Limestone
Oolitic Carbonate (CaCO3)
Labradorite (a variety of Feldspar)
Labradorite; (Na,Ca)(Al,Si)4O8 (a plagioclase feldspar)
Chalcedony
Silicon dioxide (SiO2) - Cryptocrystalline Quartz
Halite
Halite (Sodium Chloride, NaCl)
Ironstone Concretion / Limonite Node
Ferruginous Sedimentary Rock (composed primarily of Limonite FeO(OH)·nH2O and Goethite)
Coquina / Shelly Limestone
Bioclastic Limestone (composed of CaCO3)
Dyed Agate (Tumbled)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Yellow Quartz (Citrine Quartz variety / Ferruginous Quartz)
Silicon Dioxide (SiO2) with iron inclusions
Sandstone with Tafoni Weathering
Arenite (SiO2 based)
Chert (Basanite variety) with Quartz Vein
Microcrystalline Quartz (SiO2)
Montana Moss Agate
Chalcedony (SiO2) with Manganese/Iron oxide inclusions
Red Sandstone
Arenite (primarily Quartz with Hematite cement)
Sandstone (Quartz Sandstone)
Arenite (primarily SiO2)
Quartz Pebble (Chalcedony/Agate variety)
Silicon Dioxide (SiO2)
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)