Concrete
Anthropogenic Sedimentary Rock (Hydrated Calcium Silicate)
sedimentary (anthropogenic / man-made)
Category
Metamorphic Or Sedimentary Depending On Local Grade
Browse metamorphic or sedimentary depending on local grade specimens identified by the Rock Identifier community.
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Siltstone
Siltstone (primarily SiO2 with clay minerals)
sedimentary
Limonite Concretion (Ironstone)
Limonite (FeO(OH)·nH2O) with Goethite and Hematite
sedimentary
Ferruginous Sandstone (Ironstone)
Sedimentary rock with high iron oxide content (Fe2O3 / FeO(OH))
sedimentary
Ironstone Concretion (Pot Stone)
Siderite or Limonite Concretion (FeCO3 or FeO(OH)·nH2O)
sedimentary
Ironstone Concretion
Limonitic/Hematitic Concretion
sedimentary
Gossan (Iron Cap)
Limonitic Gossan (Fe2O3·nH2O mixed)
sedimentary
Chert (with Chalky Cortex)
Silicon Dioxide (SiO2)
sedimentary
Satin Spar (commonly sold as Selenite)
Hydrous Calcium Sulfate (CaSO4·2H2O)
mineral
Optical Calcite
Calcium Carbonate (CaCO3)
mineral
Chert (often called Jasper or Flint in this color variety)
Silicon Dioxide (SiO2)
sedimentary
Lapis Lazuli
Lapis Lazuli (Complex aggregate including Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)
metamorphic
Agate
Banded Chalcedony (SiO2)
mineral
Chert
Silicon dioxide (SiO2)
Sedimentary
Conglomerate
Conglomerate (Detrital sedimentary rock)
sedimentary
Gossan (Iron Hat)
Limonitic Gossan (Fe2O3·nH2O)
sedimentary
Ferruginous Sandstone
Arenite with Iron Oxide cement (primarily Fe2O3)
sedimentary
Caliche (with Lichen Cover)
Calcium carbonate-cemented soil layer (CaCO3)
sedimentary
Sandstone (specifically Arkose or Ferruginous Sandstone)
Sandstone (SiO2 with iron oxide inclusions)
sedimentary
Ironstone Concretion / Goethite Nodules
Ironstone (composed primarily of Goethite FeO(OH) and Limonite)
sedimentary
Ferruginous Sandstone
Sandstone with iron oxide (Hematite/Limonite) cement
sedimentary
Tumbled Moonstone and Amazonite Chips
Orthoclase (KAlSi3O8) and Microcline (KAlSi3O8) of the Feldspar Group
mineral
Chert (with Iron Staining)
Microcrystalline Quartz (SiO2)
sedimentary
River Pebble (Quartzite)
Quartzite (SiO2)
metamorphic
Chert (Jasper-bearing)
Microcrystalline silica (SiO2) with iron oxide inclusions
sedimentary
Sandstone with Iron Oxide Staining
Arenite with Limonite/Hematite alteration
sedimentary
Dyed Quartz Geode
Silicon Dioxide (SiO2) with artificial pigment
mineral
Banded Iron Formation (BIF) / Iron Ore
Banded Iron Formation (composed primarily of Hematite (Fe2O3) and Magnetite (Fe3O4) with Quartz/Chert)
sedimentary
River Cobble (Gneiss/Schist mix)
Foliated Metamorphic Rock (Gneissic/Schistose)
metamorphic
Lapis Lazuli
Complex mixture of minerals (lazurite, calcite, pyrite, and sodalite); (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2
metamorphic
Painted River Rock
Painted Quartzite or Smooth Siltstone
sedimentary
Pyrite
Iron Sulfide (FeS2)
mineral
Moonstone
Orthoclase Feldspar (composed of alternate layers of orthoclase and albite), (K,Na)AlSi3O8
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Shiva Lingam
Cryptocrystalline Quartz (Jasproid/Jasper)
sedimentary
Limestone (Micrite/Chalky variety)
Calcium Carbonate (CaCO3)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
sedimentary
Chert (Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Fossilized Coral
Anthozoa (Fossilized)
Sedimentary / Fossil
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
mineral
Red Garnet
Almandine (Fe3Al2(SiO4)3) or Pyrope (Mg3Al2(SiO4)3)
mineral