Limonite / Goethite (Ironstone Nodule)
Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)
mineral
Category
Mixed (Predominantly Sedimentary And Igneous)
Browse mixed (predominantly sedimentary and igneous) specimens identified by the Rock Identifier community.
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Quartz pebble in concrete
Quartz (SiO₂), embedded in Portland-cement concrete
mineral
Cobalt Blue Glass / Cullet Glass
Silicon dioxide (Amorphous man-made glass)
mineral
Granite
Felsic intrusive igneous rock
igneous
Granite Pebble
Intrusive Igneous Rock
igneous
Unakite
Unakite (altered granite)
metamorphic
Unakite
Epidotized Granite
metamorphic
Sandstone
Sedimentary Rock (Quartz Sandstone)
sedimentary
Amethyst
Silicon Dioxide (SiO2) with iron impurities
gemstone
Peach Moonstone (Orange/Peach Feldspar)
Potassium aluminum silicate (KAlSi3O8)
mineral
Tourmaline (Multi-colored)
Complex Borosilicate (Na,Ca)(Li,Mg,Al,Fe)3Al6(BO3)3Si6O18(OH)4
mineral
Amazonite
Microcline (variety Amazonite), K(AlSi3O8)
mineral
Sandstone
Arenite (SiO2 predominantly)
sedimentary
Pyrite (on Quartz/Host Rock)
Iron Sulfide (FeS₂)
mineral
Yellow Quartz (Citrine or Citrine-colored Quartz)
Silicon Dioxide (SiO2)
mineral
Pyrite with Galena and Sphalerite on Matrix
Iron Sulfide (FeS2), Lead Sulfide (PbS), Zinc Sulfide (ZnS)
mineral
Fossiliferous limestone (likely crinoidal or shell limestone)
Calcite-rich limestone; predominantly CaCO₃, with visible fossil fragments
fossil
Conglomeratic sandstone or breccia
Lithic arkose / polymictic conglomeratic sandstone
sedimentary
Amethyst (Faceted)
Quartz (SiO2) with iron impurities
Mineral
Graphite
Graphite (Carbon, C)
Mineral
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
mineral
Granite
Felsic Intrusive Igneous Rock
igneous
Sandstone
Sedimentary Rock (Quartz arenite)
sedimentary
Sandstone
Sedimentary rock composed mainly of quartz sand grains
sedimentary
Sandstone
Arenite (SiO2 dominant)
sedimentary
Flint (Chert Flake / Drill Tool)
SiO2 (Microcrystalline Quartz)
sedimentary
Sandstone (Weathered / Crushed)
Quartz Sandstone
sedimentary
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Amethyst
Amethyst (Silicon Dioxide, SiO2)
mineral
Gneiss
Metamorphic Gneiss (High-grade regional metamorphism)
metamorphic
Blue Calcite
Calcium Carbonate (CaCO3)
mineral
River Pebbles (Mixed Suite)
Mixed lithologies: Quartzite and Gneiss
metamorphic
Milky Quartz with Nephrite Jade
Silicon Dioxide (SiO2) with Ca2(Mg,Fe)5Si8O22(OH)2
mineral/metamorphic
Coarse-grained granite
Granite; predominantly quartz, potassium feldspar, plagioclase, and biotite/hornblende
igneous
Mixed Quartz and Jasper Pebbles
Silicon Dioxide (SiO2)
Mineral
Caribbean Calcite
Aragonite and Calcite (CaCO3)
mineral
Labradorite (Larvikite variety)
(Na,Ca)(Al,Si)4O8 (Plagioclase Feldspar)
igneous
Amethyst (Chevron or Banded Amethyst)
Silicon Dioxide (SiO2) with trace Iron (Fe)
mineral
Mixed Tumbled Stones Collection
Mixed Silicates and Carbonates (Quartz, Amorphous Silica, Carbonates)
multiple
Peridotite
Peridotite (predominantly Olivine and Pyroxene)
igneous
Quartz Sandstone
Quartz Arenite
sedimentary
Sandstone
Sedimentary Rock (Quartz/Feldspar grains cemented together)
sedimentary