Dalmation Stone (frequently called Dalmatian Jasper)
Peralkaline Quartz-Feldspar Rock
Category
Browse sedimentary or igneous (secondary formation) specimens identified by the Rock Identifier community.
Dalmation Stone (frequently called Dalmatian Jasper)
Peralkaline Quartz-Feldspar Rock
Labradorite
Labradorite (Plagioclase Feldspar Series: (Ca,Na)(Al,Si)4O8)
Black Tourmaline
Schorl (Sodium Iron Aluminum Borosilicate Hydroxide), NaFe3Al6(BO3)3Si6O18(OH)4
Rough Quartz (with Feldspar inclusions)
Silicon Dioxide (SiO2)
Carnelian Agate
Silicon dioxide (SiO2) - variety of chalcedony
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Chert (often called Flint or Jasper)
Silicon Dioxide (SiO2)
Fancy Jasper (Ocean Jasper or River Jasper variant)
Silicon Dioxide with inclusions (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Basalt
Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
Basalt
Basalt (Mafic Extrusive)
Basalt
Basalt (Aphanitic Mafic Volcanic Rock)
Chert (Field Stone)
Microcrystalline / Cryptocrystalline Quartz (SiO2)
Ironstone Concretion (Limonite/Goethite)
Iron oxide concretion (contains FeO(OH)·nH2O)
Stromatolite
Biogenic Sedimentary Rock (composed predominantly of CaCO3)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Chert (specifically Zebra Chert/Flint)
Silicon Dioxide (SiO2)
Sandstone
Arenite (SiO2 principal)
Chert (varieties include Flint and Jasper)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Moonstone
Orthoclase Feldspar (KAlSi3O8)
Basalt
Basalt
Diabase (Greenstone)
Diabase (Dolerite)
Basalt
Basalt (Mafic Extrusive)
Pyrite in Matrix (Fool's Gold)
Iron Sulfide (FeS2)
Limonite
Hydrous Iron Oxide (often Goethite FeO(OH), Lepidocrocite γ-FeO(OH), and other amorphous iron oxyhydroxides)
Granite
Granite (a felsic intrusive igneous rock)
Chert (Flint)
Silicon Dioxide (SiO2)
Chert (Field-collected specimen)
Chert (Crystalline Silica, SiO2)
Hematite
Iron(III) oxide (Fe2O3)
Shale or Siltstone
Sedimentary Rock (Siliciclastic)
Chert
Chert (microcrystalline quartz, SiO2)
Granite
Granite (Felsic Plutonic Rock)
Granite
Felsic Plutonic Rock (primarily SiO2, Al2O3, K2O, Na2O)
Pink Granite
Phaneritic Acidic Plutonic Rock (primarily K-feldspar, quartz, and plagioclase)
Pink Granite
Phaneritic Igneous Rock (high K-feldspar content)
Pyrite
Iron Sulfide (FeS2)
Ironstone Concretion
Siderite or Limonite Concretion
Chert (Cherty Shale / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Concretion (Sandstone)
Carbonate-cemented Sandstone Concretion
Chert (specifically Gray/Banded Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (with Lichen)
Microcrystalline Quartz (SiO2)
Pink Botswana Agate
Silicon Dioxide (SiO₂), a cryptocrystalline variety of Quartz and Chalcedony