Sandstone
Arenite (composed primarily of SiO2)
Category
Browse mineral (tectosilicate) specimens identified by the Rock Identifier community.
Sandstone
Arenite (composed primarily of SiO2)
Amygdaloidal Basalt
Basalt with secondary amygdule minerals (likely Epidote or Chlorite)
Chipped Glass/Plastic Fragment
Silicon dioxide (SiO2) for glass (amorphous) or various polymer compounds for plastic
Botryoidal Hematite (Iron Stone Conglomerate)
Hematite (Fe2O3) in sedimentary matrix
Conglomerate
Conglomerate (a clastic sedimentary rock)
Basalt with Secondary Mineral Inclusions
Amygdaloidal Basalt (Mafic volcanic rock, primarily Augite and Plagioclase)
Magnetite (Lodestone variety)
Magnetite (Iron(II,III) oxide, Fe3O4)
River/Stream Pebble
Clast / Detrital Grain / Rounded Sedimentary Particle (Compositionally variable, commonly Quartz, Feldspar, Chert, or other resistant rock fragments)
Schist
Schist (various compositions)
Dyed Howlite (simulating Lavender/Purple Jade or Charoite)
Howlite: Ca2B5SiO9(OH)5 (when natural)
Stilbite
Stilbite-Ca (NaCa4(Si27Al9)O72·28H2O)
Quartz (Orangey-white variety)
Silicon Dioxide (SiO2)
Yellow Apatite Sphere (Polished)
Fluorapatite / Ca5(PO4)3F
Garnet Schist
Almandine Garnet Schist
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Quartz (Smoky/Milky variety)
Silicon Dioxide (SiO2)
Rough Quartz (with potential Host Rock)
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Garnet (Almandine/Pyrope series)
Silicate mineral (Almandine: Fe3Al2Si3O12; Pyrope: Mg3Al2Si3O12)
Banded Calcite (often sold as 'Mexican Onyx' or 'Calcite Onyx')
Calcite (Calcium Carbonate, CaCO3)
Schist
Schist
Peacock Ore (Bornite or Chalcopyrite)
Bornite (Cu₅FeS₄) or iridescent Chalcopyrite (CuFeS₂)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Milky Quartz with Chlorite/Epidote inclusions
Silicon Dioxide (SiO2) with phyllosilicate/sorosilicate inclusions
Olivine (Peridot when gem-quality)
Olivine Group (Magnesium Iron Silicate, (Mg,Fe)2SiO4)
Quartz (Smoky/Grey Quartz Variant)
Silicon Dioxide (SiO2)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Quartz / Quartzite Fragment
Silicon Dioxide (SiO2)
Mahogany Obsidian
Volcanic glass containing Magnetite/Hematite
Orthoclase Feldspar
KAlSi3O8 (Potassium Aluminum Silicate)
Orthoclase Feldspar
Potassium Aluminum Silicate (KAlSi3O8)
Quartz / Quartzite Pebble
Silicon Dioxide (SiO2)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Orthoclase Feldspar
Potassium aluminum silicate (KAlSi3O8)
Blue Apatite
Apatite (Group), Ca5(PO4)3(F,Cl,OH)
Quartz Pebble (Iron-stained)
Silicon Dioxide (SiO2)
Quartz (Common or Milky Quartz)
Silicon Dioxide (SiO2)