Chert with Epidote and Jasper inclusions
SiO2 (Silicon Dioxide) with Ca2(Al, Fe)3(SiO4)3(OH) inclusions
sedimentary
Category
Mineralogical Specimen
Browse mineralogical specimen specimens identified by the Rock Identifier community.
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Quartz / Calcite Vein Rock
Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3)
mineral
Weathered granite or granitic gneiss pebble
Granite, chiefly quartz (SiO₂), feldspar, and biotite/hornblende; exact identification is uncertain from the image
igneous
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Pyrite in Matrix
Iron Sulfide (FeS2)
mineral
Mica-rich metamorphic rock, likely phyllite or mica schist
Quartz–muscovite phyllite/schist; commonly dominated by muscovite mica, quartz, and minor feldspar
metamorphic
Mixed gravel and small stones
Unsorted gravel; individual clasts are not identifiable from the image
sedimentary
Quartz-rich stone, possibly aventurine quartz or quartzite
Quartz (SiO₂), likely massive or microcrystalline; exact identification requires testing
mineral
Polished picture jasper
Silicified microcrystalline quartz (chalcedony), commonly called picture jasper
sedimentary
Small polished dark mineral or gemstone fragment
Indeterminate; possibly smoky quartz, obsidian, or dark tourmaline
mineral
Granite Cobble
Phaneritic Felsic Igneous Rock
igneous
Chert / Green Jasper
Silicon Dioxide (SiO2)
sedimentary
Jasper with Chalcedony
Silicon Dioxide (SiO2)
mineral
Yellow Quartzite (River Pebble)
Quartzite (SiO2)
metamorphic
Chalcedony with Druzy Quartz Geode
Silicon Dioxide (SiO2)
mineral
Coarse granite (likely weathered biotite granite)
Granite; quartz + feldspar + biotite/hornblende, approximate composition 20–60% quartz and abundant K-feldspar/plagioclase
igneous
Jasper / Chert (river tumbled)
Microcrystalline Quartz (SiO2)
sedimentary
Pegmatite with Schorl (Black Tourmaline) and Mica
Pegmatite (complex association of NaAlSi3O8, NaFe3Al6(BO3)3Si6O18(OH)4, and KAl2(AlSi3O10)(OH,F)2)
igneous
Quartz-veined metamorphic rock, likely greenschist or altered metavolcanic
Chlorite–actinolite–epidote-bearing metavolcanic rock with quartz veins; exact identification requires testing
metamorphic
Crackle Agate / Dyed Quartz
SiO2 (Silicon Dioxide)
mineral
Reddish-brown, iron-stained rock fragment
Indeterminate; possibly weathered porphyritic volcanic rock
igneous
Chert (Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Labradorite
Labradorite ((Ca, Na)(Al, Si)4O8)
mineral
Weathered quartz-bearing rock, possibly granitic gneiss
Quartz–feldspar–mica aggregate; exact identification requires testing
metamorphic
Red garnet crystal cluster
Most likely almandine garnet, Fe₃Al₂(SiO₄)₃; exact species cannot be confirmed from the image alone.
mineral
Sedimentary Breccia
Breccia (Clastic Sedimentary Rock)
sedimentary
N/A (Non-Geological Specimen)
N/A
Quartz on Host Rock
Silicon Dioxide (SiO2)
mineral
Quartz (Smoky/Grey variety)
Silicon Dioxide (SiO2)
mineral
Small brown mineral specimen, possibly mica-bearing rock
Unidentified from the image; exact mineral species cannot be determined at this scale
mineral
Greenschist
Greenschist (Chlorite-Epidote-Actinolite Schist)
metamorphic
Desert Rose
Gypsum (CaSO4·2H2O) or Baryte (BaSO4)
mineral
Agate
Cryptocrystalline quartz (SiO2)
mineral
Sandstone (Iron-stained Pebble)
Sandstone (Quartz/Hematite dominated)
sedimentary
Peanut Wood
Petrified Wood (Silicified Araucaria with Teredo boreholes)
fossil
Jasper
Silicon dioxide (SiO2)
sedimentary
Amethyst
Silicon Dioxide (SiO2) containing iron impurities and irradiation
mineral
Emerald in Host Rock
Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities
mineral
Tiger's Eye
Silicon dioxide with fibrous inclusions (SiO2)
mineral
Red Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Quartz with Tourmaline and Iron Staining
Silicon Dioxide (SiO2) with accessory tourmaline and limonite
mineral
Jasper
Silicon Dioxide (Microcrystalline Quartz, SiO2)
sedimentary