River Pebble (Likely Quartzite or Gneiss)
Metamorphosed Silicate Rock (primarily SiO2)
metamorphic
Category
Metamorphic Rock (Primarily Composed Of Minerals)
Browse metamorphic rock (primarily composed of minerals) specimens identified by the Rock Identifier community.
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Muscovite Mica
Muscovite (Potassium Aluminum Silicate Hydroxide Fluoride), KAl2(AlSi3O10)(OH,F)2
mineral
Limonite (Yellow Ochre)
FeO(OH)·nH2O (Hydrous iron(III) oxide-hydroxide mixture)
Mineral (Iron Ore)
Banded Chert
Microcrystalline Quartz (SiO2)
sedimentary
Breccia
Clastic Breccia
sedimentary
Mixed Mineral Specimens
Mixed Silicates, Oxides, and Phosphates (SiO₂, Ca₅(PO₄)₃(F,Cl,OH), Na₈Al₆Si₆O₂₄Cl₂, etc.)
mineral
Basalt with Plagioclase Phenocrysts
Porphyritic Basalt (primarily SiO2, MgO, FeO, and CaO)
Igneous
Montana Moss Agate
Chalcedony (SiO2) with Manganese/Iron oxide inclusions
sedimentary
Muscovite Mica
Muscovite: KAl2(AlSi3O10)(OH)2
mineral
Granite
Granite (phaneritic felsic intrusive rock)
igneous
Quartzite
Quartzite (primarily SiO2)
metamorphic
Quartzite
Quartzite (primarily SiO2)
metamorphic
Kaolinite (Kaolin)
Kaolinite (Al2Si2O5(OH)4)
mineral
Aventurine Quartz
Silicon Dioxide (SiO2) with inclusions of Fuchsite mica
mineral
Quartzite (Iron-stained)
Metamorphosed Quartz-rich Rock (SiO2)
metamorphic
Orange Calcite (with White Calcite/Quartz matrix)
Calcium Carbonate (CaCO3)
mineral
Rhodonite (in matrix)
Rhodonite (Mn,Fe,Mg,Ca)SiO3
Mineral
Ruby (varieties of Corundum)
Aluminum oxide (Al2O3) with Chromium traces
mineral
Montana Moss Agate
Chalcedony (Silicon Dioxide, SiO2)
mineral
Granite
Phaneritic Igneous Rock (composed mostly of Quartz, Feldspar, and Mica)
igneous
Turquoise
Turquoise, CuAl6(PO4)4(OH)8·4H2O
mineral
Sodalite Syenite (popularly known as Yooperlite)
Sodalite-rich Syenite (composed of alkali feldspar and sodalite)
Igneous
Red Quartz
Silicon Dioxide (SiO2) with Hematite inclusions
mineral
Yellow Aventurine
Quartzite with inclusions (SiO2)
metamorphic
Banded River Cobble with Mafic Dike
Hydrothermally altered Graywacke or Sandstone with Mafic Intrusion
igneous and sedimentary
Quartzite Pebble
Metamorphosed Quartz Sandstone (SiO2)
metamorphic
Granite (Light-colored quartz/feldspar variety)
Granite (composed primarily of Quartz SiO2 and Feldspar KAlSi3O8)
igneous
Green Aventurine
Tectosilicate, variety of Quartz (SiO2) containing Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)
mineral
Schist
Mica Schist
metamorphic
Unakite
Unakite epidotized granite
metamorphic
Diorite (Polished Cobble)
Diorite (Intermediate intrusive igneous rock)
Igneous
Ruby
Corundum (Al2O3 with Chromium trace impurities)
mineral
Quartzite River Rock
Quartzite (primarily SiO2)
metamorphic
Yellow Quartzite (River Pebble)
Quartzite (primarily SiO2)
metamorphic
Quartzite
Quartzite (primarily SiO2)
metamorphic
Quartzite
Quartzite (primarily SiO2)
metamorphic
Quartzite
Quartzite (primarily SiO2)
metamorphic
Quartzite with Quartz Veining
Quartzite (primarily SiO2)
metamorphic
Quartz (Iron-stained or Rose variant)
Silicon Dioxide (SiO2)
mineral
Diorite
Diorite (Intermediate intrusive igneous rock)
igneous
Fossilized Bone Fragment
Permineralized Vertebrate Bone (Hydrox yapatite replaced by Silica or Calcite)
sedimentary
Ironstone Concretion (Limonite/Goethite)
Goethite-rich Concretion (FeO(OH))
sedimentary