Pyrite
Iron Sulfide (FeS2)
mineral
Category
Sedimentary Or Metamorphic (Low Grade)
Browse sedimentary or metamorphic (low grade) specimens identified by the Rock Identifier community.
Learn about Sedimentary Or Metamorphic (Low Grade) in the encyclopedia
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Lapis Lazuli
Na6Ca2(Al6Si6O24)(S,SO4,Cl)1-2 (primarily containing Lazurite with inclusions of Calcite and Pyrite)
metamorphic
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Emerald in Matrix
Beryl (Be3Al2Si6O18) with trace amounts of Chromium/Vanadium
mineral
Siltstone
Siltstone (primarily SiO2 with clay minerals)
sedimentary
Unakite
Epidote–orthoclase–quartz metamorphic rock
metamorphic
Epidosite (Epidote-rich rock)
Epidosite (consisting primarily of Epidote: {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH))
metamorphic
Quartz-rich metamorphic pebble, possibly jade-like greenstone
Likely quartzite or altered basalt/greenstone; visible minerals may include quartz, feldspar, chlorite/epidote, and iron oxides
metamorphic
Serpentine-rich pebble
Serpentinite; chiefly serpentine-group minerals (chrysotile, lizardite, antigorite), commonly with magnetite and minor olivine/pyroxene
metamorphic
Tiger's Eye
Silicon dioxide (SiO2) - Pseudomorph after crocidolite
mineral
Turquoise (likely Sleeping Beauty variety or treated Howlite imitation)
Hydrated phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O
mineral
Pyrite in Matrix
Iron Sulfide (FeS2)
mineral
Anthracite Coal
Anthracite (Carbon-rich metamorphic coal)
metamorphic
Anthracite Coal
Anthracite
metamorphic
Weathered, porous limestone (probable fossiliferous limestone)
Calcite-rich limestone; predominantly CaCO₃
sedimentary
Grey Chalcedony
Silicon Dioxide (SiO2)
mineral
Chalcedony (Common Opal variant)
Silicon dioxide (SiO2) with varying levels of hydration
mineral
Garnet (Spessartine / Almandine)
Fe3Al2(SiO4)3 to Mn3Al2(SiO4)3 (Nesosilicate)
mineral
Anthracite Coal
Anthracite
sedimentary
Rough Ruby
Corundum (Al2O3 with Chromium impurities)
mineral
Serpentinite
Serpentinite (complex silicate minerals including Mg3Si2O5(OH)4)
metamorphic
Serpentinite
Serpentinite (composed mainly of Group: Serpentine; (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4)
metamorphic
Mixed river stones and gravel
Polymictic alluvial clasts; individual pieces may include quartzite, granite, basalt, sandstone, limestone, and slate
igneous, sedimentary, metamorphic
Chert
Silicon dioxide (SiO2) - Microcrystalline quartz
Sedimentary
Lavender Jade and Snowy Quartz (Druzy)
NaAlSi2O6 (Jadeite) / SiO2 (Quartz)
metamorphic
Carnelian
Silicon Dioxide (Chalcedony variety)
gemstone
Agate
Silicon Dioxide (Chalcedony), SiO2
sedimentary
Serpentinite
Serpentinite (composed primarily of minerals in the serpentine group: (Mg,Fe)3Si2O5(OH)4)
metamorphic
Beryl (Emerald variety in host rock)
Be3Al2(SiO3)6 (Silicate mineral)
mineral
Ironstone / Limonite Concretion
Hydrated Iron Oxide Rock (FeO(OH)·nH2O with SiO2)
sedimentary
Conglomerate
Conglomeratic Sandstone
sedimentary
Coal (likely Anthracite)
Anthracite coal
sedimentary
Serpentine
Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4
metamorphic
Agate
Chalcedony (SiO2)
sedimentary
Unakite (likely)
Epidote–pink feldspar–quartz rock; commonly termed unakite
metamorphic
Limonite (Iron Ore/Hydrated Iron Oxide)
Limonite (mixture of FeO(OH)·nH₂O minerals, mainly Goethite, FeO(OH) and Lepidocrocite, FeO(OH))
Mineral
Nephrite Jade
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)
metamorphic
Siltstone
Siltstone (composed of clastic quartz and feldspar)
sedimentary
Greywacke (Stream Pebble with Quartz/Calcite Veins)
Greywacke sandstone / Metagraywacke
sedimentary
Sandstone (likely Quartzite-grade)
Arenite (primarily SiO2)
sedimentary
Anthracite Coal
Anthracite
metamorphic
Iolite (Cordierite)
Magnesium Iron Aluminum Silicate (Mg,Fe)2Al4Si5O18
mineral