Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
Category
Browse metamorphic or sedimentary specimens identified by the Rock Identifier community.
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
Jasper with Epidote
Silicon Dioxide (SiO2) with Calcium Aluminum Iron Sorosilicate [Ca2Al2Fe3+Si3O12(OH)]
Blue Aventurine
Silicon Dioxide (SiO2) containing Dumortierite or Crocidolite inclusions
Rhodonite
Rhodonite (Mn,Fe,Mg,Ca)SiO3
Green Aventurine
Quartz with Fuchsine inclusions (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Corundum
Corundum (Aluminium oxide, Al2O3)
Epidote
Epidote ({Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH))
Zebra Jasper
Silicon Dioxide (SiO2) with various inclusions
Sandstone and Quartzite Specimens
SiO2 with varying mineral/clastic inclusions
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Seraphinite (Clinochlore)
Clinochlore (Mg,Fe2+)5Al(Si3Al)O10(OH)8
Rhodonite
Manganese silicate (Mn,Fe,Mg,Ca)SiO3
Biotite or Phlogopite Mica
K(Mg,Fe)3(AlSi3O10)(F,OH)2
Jasper
Chalcedony (Microcrystalline Quartz) - SiO2
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Sapphire
Corundum (Al2O3)
Bornite (Peacock Ore)
Bornite (Cu5FeS4)
Magnetite
Iron(II,III) oxide (Fe3O4)
Bornite (Peacock Ore)
Bornite (Cu5FeS4)
Garnet (likely Almandine or a blend)
Garnet group: X3Y2(SiO4)3, where X can be Ca, Mg, Fe2+, Mn2+ and Y can be Al, Fe3+, Cr3+. Given the dark, somewhat reddish-brown appearance in the image, it's likely Almandine (Fe3Al2(SiO4)3) or a mix with other iron-rich garnets.
Mica Schist
Mica Schist (primarily Muscovite or Biotite sheet silicates)
Quartz Pebble
Silicon Dioxide (SiO2)
Garnet
Almandine-Pyrope group, X3Y2(SiO4)3
Magnetite (Charnockite Regional Variation)
Magnetite (Fe3O4)
Epidote in Quartz
Quartz with Epidote inclusions (SiO2 with Ca2(Al,Fe)3(SiO4)3(OH) inclusions)
Banded Gneiss (with possible weathered sulfide or iron staining)
Gneiss, potentially with iron oxide/hydroxide staining (e.g., limonite) or weathered sulfides
Banded Gneiss
Gneiss
Rhodonite
Rhodonite (Mn, Fe, Mg, Ca)SiO3
Green Aventurine
Aventurine Quartz (SiO2 with Fuchsite inclusions)
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Fuchsite Gneiss or Schist
Muscovite (variety Fuchsite) within Metamorphic Host Rock
Quartz
Quartz (SiO₂)
Greenschist
Chlorite-actinolite schist
Banded Gneiss
Gneiss (pronounced "nice")
Tiger Iron
Banded Iron Formation (BIF)
Jasper and Quartz River Cobble
Silicon Dioxide (SiO2) with Hematite inclusions
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.
Dumortierite Quartz
Al7BO3(SiO4)3O3 (Aluminum borate silicate)
Fuchsite (Chrome Mica)
K(Al,Cr)2(AlSi3O10)(OH)2
White Quartz
Quartz (SiO2)
Anthracite Coal
Anthracite (Carbon-based organic sedimentary rock exposed to metamorphic heat/pressure; Chemical composition is approximately 86%–98% Carbon)