Mica schist (likely biotite-rich schist)
Mica schist, composed chiefly of mica-group minerals (likely biotite) with quartz and feldspar
metamorphic
Category
Minerals
Browse minerals specimens identified by the Rock Identifier community.
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Small quartz-rich mineral fragment
Quartz (SiO₂), possibly milky or chalcedonic quartz
mineral
Limonite Concretion
Hydrated Iron Oxide-Hydroxide, FeO(OH)*nH2O
mineral
Small water-worn pebble, likely granite or granitic rock
Granite (tentative; exact identification is uncertain from the photo)
igneous
Magnetite-rich Basalt
Basalt containing Fe3O4
igneous
Iron-stained weathered volcanic rock (probable basalt/andesite)
Altered basaltic–andesitic rock, chiefly plagioclase and pyroxene with iron oxides/hydroxides
igneous
Weathered iron-rich limestone or marl
Calcitic carbonate rock with limonite/goethite and clay impurities (predominantly CaCO₃)
sedimentary
Quartz and Mixed Sedimentary Rocks
Silicon Dioxide (SiO2) mixed with various clastic sedimentary lithologies
sedimentary
Ruby in Kyanite
Corundum in Disthene (Al2SiO5 + Al2O3)
metamorphic
Quartz Boulder
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
sedimentary
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartz pebble
Silicon Dioxide (SiO2)
mineral
Quartz (Small Pebble)
Silicon Dioxide (SiO2)
mineral
Granite
Granite
igneous
Vesicular basalt
Basalt, a mafic volcanic rock composed mainly of plagioclase feldspar, pyroxene, and often olivine
igneous
Milky quartz
Quartz (silicon dioxide, SiO₂)
mineral
Greenstone / Greenschist
Greenschist facies metamorphic rock (composed primarily of chlorite, actinolite, and epidote)
metamorphic
Gneiss
Gneiss
metamorphic
Goethite
Goethite (alpha-FeO(OH))
mineral
Likely biotite-rich schist (mica schist)
Mica schist, chiefly quartz + biotite mica (K(Mg,Fe)₃AlSi₃O₁₀(F,OH)₂), possibly with muscovite and feldspar
metamorphic
Vesicular basalt (likely scoriaceous basalt)
Basalt, primarily plagioclase + pyroxene ± olivine; iron-oxide staining
igneous
Milky quartz (possibly quartz-rich pegmatite)
Quartz, silicon dioxide (SiO₂)
mineral
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Granite
Coarse-grained felsic intrusive igneous rock; mainly quartz, potassium feldspar, plagioclase, and biotite/hornblende
igneous
Biotite-bearing granite
Granite, composed mainly of quartz (SiO₂), potassium feldspar, plagioclase, and biotite mica
igneous
Greenstone (Epidote/Chlorite Rich Rock)
Metabasalt (often contains Epidote Ca2Al2(Fe3+;Al)(SiO4)(Si2O7)O(OH))
metamorphic
Milky Quartz with Iron Staining
Quartz (Silicon Dioxide, SiO2)
mineral
Greenstone with Epidote or Quartz veins
Metabasalt (Greenstone facies)
metamorphic
Chert (specifically Green Chert/Jasper)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Mixed polished stone and mineral collection
Several small, tumbled specimens; individual species cannot be identified reliably from the image
mineral
Limonite
FeO(OH)•nH2O
mineral
Granite with a quartz-rich inclusion
Granite, composed mainly of quartz, feldspar, and mica
igneous
Granite Gneiss
Granitic Gneiss
Metamorphic
Limonite
FeO(OH)•nH2O
mineral
Tumbled blue-green stone, likely turquoise or chrysocolla
Turquoise: CuAl₆(PO₄)₄(OH)₈·4H₂O; chrysocolla: hydrated copper aluminosilicate
mineral
Yellow Jade (often Serpentine or Dolomite)
Primarily Serpentine (Mg3Si2O5(OH)4) or Dolomite (CaMg(CO3)2), though the term 'yellow jade' is also sometimes applied to varieties of true nephrite or jadeite.
Mineral, often a rock given its aggregate nature
Quartz Crystal Cluster
Silicon Dioxide (SiO2)
mineral