Chert (often called Flint in archaeological contexts)
Microcrystalline or cryptocrystalline Silica (SiO2)
sedimentary
Category
Metamorphic Or Igneous (Context Dependent)
Browse metamorphic or igneous (context dependent) specimens identified by the Rock Identifier community.
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Rutilated Quartz
Quartz (SiO2) with Rutile (TiO2) inclusions
Mineral
Lapis Lazuli
Lapis lazuli (Complex silicate rock containing Lazurite (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2, Calcite, and Pyrite)
metamorphic
Nephrite Jade
Ca2(Mg, Fe)5Si8O22(OH)2
metamorphic
Lapis Lazuli
Na8(Al6Si6O24)S2 (Lazurite is the primary constituent mineral)
metamorphic
Milky Quartz with Iron Oxide Weathering
Silicon Dioxide (SiO2) with Goethite/Limonite coatings
mineral
Fossiliferous limestone (likely crinoidal or shell limestone)
Calcite-rich limestone; predominantly CaCO₃, with visible fossil fragments
fossil
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Schist
Schist (Crystalline Metamorphic Rock)
metamorphic
Greenschist / Serpentinite
Metamorphic rock rich in chlorite/actinolite/serpentine
metamorphic
Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Weathered foliated metamorphic rock, likely gneiss or schist
Quartz–feldspar–mica metamorphic rock; exact identification requires a fresh surface and mineral tests
metamorphic
Milky Quartz Pebble with Matrix
Silicon Dioxide (SiO2)
mineral
Schist (specifically Chlorite/Greenschist)
Chlorite Schist
metamorphic
Serpentine
Serpentine group (Mg,Fe,Ni,Al,Zn,Mn)3(Si,Fe,Al)2O5(OH)4
metamorphic
Gneiss
Gneiss
metamorphic
Unakite
Epidotized Granite
metamorphic
Anyolite (Ruby in Zoisite)
Zoisite with inclusions of Hornblende and Ruby (Ca2Al3(SiO4)3(OH))
metamorphic
Greenstone Pebble
Metabasalt / Greenschist
metamorphic
Lapis Lazuli
Lapis Lazuli (Primary mineral: Lazurite, (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)
metamorphic
Mixed mineral and rock collection
Predominantly quartz varieties, including amethyst, plus likely calcite, feldspar, mica, and miscellaneous polished stones
mineral
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Quartz
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
K-Feldspar (Potassium Feldspar)
Potassium Feldspar (KAlSi3O8)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Quartz pebble
Silicon dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Quartz Boulder
Silicon Dioxide (SiO2)
mineral
Raw Quartz
Silicon Dioxide (SiO2)
mineral
Quartz pebble
Silicon dioxide (SiO2)
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Yellow Quartz (Citrine / Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Quartz (River Pebble)
Silicon Dioxide (SiO2)
mineral
Quartz (Quartz Pebble)
Silicon Dioxide (SiO2)
mineral
Quartz (Smoky Quartz / Chalcedony)
Silicon Dioxide (SiO2)
mineral