Mica Schist
Muscovite Schist (KAl2(AlSi3O10)(OH)2)
metamorphic
Category
Mineralogical Specimen
Browse mineralogical specimen specimens identified by the Rock Identifier community.
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Quartzite
Quartzite (SiO2)
metamorphic
Crystalline Quartz (Rough)
Quartz (Silicon Dioxide, SiO2)
mineral
Basalt
Basalt (Mafic volcanic rock)
igneous
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Milky quartz
Quartz, silicon dioxide (SiO₂)
mineral
Sandstone Pebble
Arenite (SiO2 based)
sedimentary
Porphyritic Andesite
Andesite (porphyritic variety)
igneous
Quartzite River Rock
Quartzite
metamorphic
Sandstone (Banded)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Amethyst Geode Segment
Silicon Dioxide (SiO2) with trace Iron impurities
mineral
Golden Healer Quartz (Iron-Stained Quartz)
Silicon Dioxide (SiO2) with Iron Oxide/Hydroxide inclusions
mineral
Calcite in Matrix
Calcium Carbonate (CaCO3)
mineral
Man-made Crystal (Lead Glass)
Lead oxide-doped Silica Glass (approx. SiO2 + PbO)
Mineraloid/Synthetic Material
Chalcedony / Agate with Botryoidal Quartz
Silicon Dioxide (SiO2)
sedimentary
Jasper Breccia
Silicon Dioxide (SiO2) - Brecciated Microcrystalline Quartz
sedimentary
Green Fluorite
Calcium Fluoride (CaF2)
mineral
Likely tumbled calcite or pale limestone fragment
Calcite (CaCO₃), possibly microcrystalline limestone
mineral
Sandstone (Siltstone or Fine-grained)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Garnet (Almandine-Pyrope)
Almandine-Pyrope Mg3Al2(SiO4)3 to Fe3Al2(SiO4)3
mineral
Chert (Common Opal/Jasper mix)
Silicon Dioxide (SiO2) with impurities
sedimentary
Jasper Agate (Carnelian Jasper)
Silicon Dioxide (SiO2) with iron oxide inclusions
mineral
Blue Lace Agate
Microcrystalline Quartz (Chalcedony), SiO2
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Jasper
Silicon Dioxide (Microcrystalline Quartz / Chalcedony)
sedimentary
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Pyrite in Matrix with Copper Alterations
Iron Sulfide (FeS2) with secondary Copper carbonates/sulfides
mineral
Banded Agate
Silicon dioxide (SiO2)
mineral
Green Aventurine
Silicon Dioxide with Fuchsite inclusions (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)
mineral
Rough Quartz (Clear Quartz)
Silicon Dioxide (SiO2)
mineral
Milky Quartz with Iron Inclusions
Silicon Dioxide (SiO2)
mineral
Weathered gray stone, possibly limestone or concrete-like carbonate rock
Tentatively micritic limestone (calcium carbonate, CaCO₃); exact identification is uncertain from the image
sedimentary
Tumbled brown chalcedony or jasper
Microcrystalline quartz (SiO₂), likely iron-stained chalcedony/jasper
mineral
Tumbled green aventurine (probable)
Quartz, SiO₂, with green fuchsite mica inclusions
mineral
Fossiliferous Flint or Chert with Bryozoan Fossils
Sedimentary cryptocrystalline quartz (SiO2) with fossil inclusions
sedimentary
Polished green aventurine
Quartzite or quartz-rich rock containing fuchsite mica; mainly SiO₂
mineral
Agate
Silicon Dioxide (Chalcedony), SiO2
sedimentary
Chert (Concretion or Nodular Variety)
Microcrystalline Quartz (SiO2)
sedimentary
Quartz Vein in Matrix / Quartzite
Silicon Dioxide (SiO2) with host rock
metamorphic
Peridotite
Ultramafic intrusive rock (Peridotite / Dunite)
igneous
Granite Pebble
Granite (Phaneritic Igneous Rock)
igneous
Coral Fossil (Hexagonaria)
Hexagonaria sp. (Silica-replaced)
fossil