Schist
Mica schist, likely muscovite–biotite schist with quartz and feldspar
metamorphic
Category
Mineral (Tectosilicate)
Browse mineral (tectosilicate) specimens identified by the Rock Identifier community.
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Limonite/Goethite Nodule
Iron Oxyhydroxide (primarily FeO(OH)·nH2O)
mineral
Fossilized bone or tooth fragment
Indeterminate fossil bone; possibly mammalian or reptilian
fossil
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Volcanic Rock)
Igneous
Granite
Granite (phaneritic felsic intrusive rock)
igneous
Banded Gneiss
Gneiss (pronounced 'nice')
metamorphic
Vein Quartz in Basalt or Mafic Rock
Silicon Dioxide (Quartz veins in volcanic host rock)
igneous
Concretion
Septarian Concretion
sedimentary
Limonite Nodule
FeO(OH)·nH2O (Hydrated iron oxide-hydroxide)
mineral
Sandstone with Magnetite and Iron Staining
Clastic Sedimentary Rock (contains Fe3O4 and Limonite/Hematite)
sedimentary
Chrysocolla (or Turquoise/Aventurine)
Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O
mineral
Sandstone
Arenite (SiO2 based with various mineral cements)
sedimentary
Quartz Pebbles
Silicon Dioxide (SiO2)
mineral
K2 stone (azurite–granite)
Biotite granite hosting blue azurite (Cu₃(CO₃)₂(OH)₂), often with malachite and quartz
igneous
Sandstone Concretion
Clastic sedimentary rock (primarily Quartz SiO2 with mineral cement)
sedimentary
Vanadinite
Pb5(VO4)3Cl
mineral
Iron-stained Quartz
Silicon Dioxide (SiO2) with Iron Oxide (Limonite/Goethite) inclusions
mineral
Polished Hematite Tower
Hematite (Fe2O3)
mineral
Milky Quartz with Iron Staining
Silicon Dioxide (SiO2) with Limonite/Goethite
mineral
Stalagmite (Flowstone)
Speleothem (Calcium Carbonate, CaCO3)
sedimentary
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Quartz Geode Fragment
Silicon Dioxide (SiO2)
mineral
Azurite and Malachite on Matrix
Cu3(CO3)2(OH)2 (Azurite) and Cu2CO3(OH)2 (Malachite)
mineral
Epidote
Epidote (Ca2(Al, Fe)3(SiO4)3(OH))
mineral
Fossil Shark Tooth
Odontaspididae (Sand Tiger Shark family)
fossil
Boxwork Siderite or Sepatarian Nodule Weathering
Siderite (FeCO3) with secondary mineralization or Boxwork Geode fragment
sedimentary
Vesicular basalt (scoriaceous basalt)
Basalt, primarily plagioclase, pyroxene, and iron-rich olivine; vesicular variety may be termed scoria
igneous
Magnetite Sand (Black Sand)
Magnetite (Fe3O4)
mineral
Quartz vein in host rock
Quartz (SiO₂), likely in a weathered carbonate or sedimentary matrix
mineral
Tumbled serpentine (likely bowenite/antigorite)
Serpentine-group minerals, chiefly antigorite or lizardite; commonly Mg₃Si₂O₅(OH)₄
metamorphic
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Bauxite
Bauxite (mixture of Hydrous Aluminum Oxides)
sedimentary
Sandstone
Arenite (clastic sedimentary rock)
sedimentary
Polished mixed rock, likely orbicular/epidote-bearing granite or basalt
Uncertain; probable quartz–feldspar–amphibole/epidote aggregate
igneous
Limonite (Oxidized Iron Ore)
FeO(OH)·nH2O (Hydrous ferric oxide)
mineral
Chrysocolla
Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4·nH2O
mineral
Tooth fossil, likely mammalian or reptilian fragment
Indeterminate fossilized tooth; enamel and dentine, taxon unresolved
fossil
Granitic Gneiss
Gneiss (Metamorphic rock predominantly containing quartz, K-feldspar, and plagioclase)
metamorphic
Schist
Mica Schist
metamorphic
Botryoidal calcite (likely calcite concretion)
Calcite, calcium carbonate (CaCO₃)
mineral
Green Fluorite
Calcium Fluoride (CaF2)
mineral