Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
mineral
Category
Metamorphic Rock (Primarily Composed Of Minerals)
Browse metamorphic rock (primarily composed of minerals) specimens identified by the Rock Identifier community.
Learn about Metamorphic Rock (Primarily Composed Of Minerals) in the encyclopedia
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Sandstone (Quartzose Sandstone)
Clastic Sedimentary Rock (composed mostly of SiO2)
sedimentary
Sandstone
Arenite
sedimentary
Schist
Schist (various mineralogical compositions including mica, chlorite, talc, etc.)
Metamorphic
Greenstone
Metabasalt / Metamorphosed Igneous Rock
metamorphic
Gastropod Fossil (Snail Steinkern)
Class Gastropoda fossil, composed of Calcium Carbonate (CaCO3)
sedimentary
Red Sandstone (Siltstone/Mudstone variety)
Ferruginous Sandstone (composed primarily of Quartz with Hematite cementation)
sedimentary
Black Star Diopside
Diopside (CaMgSi2O6) with asterism
Mineral
Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Greenschist
Chlorite-actinolite schist
metamorphic
Magnetite
Magnetite (Fe3O4)
mineral
Demitasse Granite (Diorite-Granite transition)
Intermediate Plutonic Rock (Granodiorite/Diorite mix)
igneous
Gneiss (Cobble)
Gneiss
metamorphic
Quartz (Pebble)
Quartz (SiO₂)
Mineral
Quartz (likely)
Quartz (SiO2 - Silicon Dioxide)
Mineral
Quartz Vein in Host Rock
Hydrothermal Quartz (SiO2) in Slates/Schists
metamorphic
Quartz on Schist
Silicon Dioxide (SiO2) on Foliated Metamorphic Rock
metamorphic
Sandstone (likely Arkose or Quartz Sandstone)
Arenite (SiO2 + varied clasts)
sedimentary
Gneiss
High-grade Metamorphic Gneiss
metamorphic
Fossiliferous Limestone
Limestone (composed primarily of calcite with included fossils CaCO3)
Sedimentary
Greenstone
Metabasalt / Greenstone
metamorphic
Gneiss
Gneiss
metamorphic
Granite Gneiss
Gneiss (High-grade metamorphic rock formed from granitic precursor)
metamorphic
Milky Quartz
Quartz (Silica / Silicon Dioxide), SiO2
mineral
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Blue Quartz (potentially Dumortierite-included)
Silicon Dioxide (SiO2) with inclusions
mineral
Blue Tiger's Eye
Crocidolite in Quartz (altered)
Mineral
Vesicular Basalt
Basalt (extrusive volcanic rock)
igneous
Diamond (Cut Specimen)
Diamond (pure carbon, C)
mineral
Rhodonite
Manganese Silicate (MnSiO₃)
mineral
Raw Diamond
Carbon (C)
mineral
Sandstone (Ferruginous)
Arenite with Iron-Oxide cement
sedimentary
Blue Chalcedony and Picture Jasper Beads
Blue Chalcedony (SiO2), Picture Jasper (SiO2)
Mineral
Limonite Concretion
Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)
sedimentary
Greenstone
Greenschist
metamorphic
Mica Schist
Mica Schist (Intermediate-grade Metamorphic Rock)
metamorphic
Felsic Drill Core (likely Gneiss or Granite)
Felsic Metamorphic Rock (Gneissic profile)
metamorphic
Schist (Garnet-Mica Schist)
Garnet-Mica Schist
metamorphic
Epidote
Epidote (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))
metamorphic
Smoky Quartz and Biotite Schist
Quartz-Biotite Schist (SiO2 + K(Mg,Fe)3AlSi3O10(F,OH)2)
metamorphic
Granite
Granite (a broadly defined plutonic igneous rock, often more specifically classified as quartz monzonite or granodiorite based on precise mineral percentages)
igneous
Sandstone (with Iron Staining)
Arenite (primarily SiO2 with Fe2O3/FeO(OH) oxides)
sedimentary