Sandstone
Arenite (primarily SiO2)
Category
Browse industrial byproduct (often mistaken for obsidian or mineral) specimens identified by the Rock Identifier community.
Sandstone
Arenite (primarily SiO2)
Garnet (Almandine)
Almandine (Fe3Al2(SiO4)3)
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) within Sedimentary/Metamorphic Matrix
Sandstone (Quartzose Sandstone)
Clastic sedimentary rock (primarily SiO2)
Nickel
Nickel (Ni)
Rough Diamond
Diamond (pure carbon, C)
Golden Healer Quartz
Ferruginous Quartz (SiO2 with Fe2O3 inclusions)
Iron-stained Quartz (Gossan/Limonite-coated Quartz)
Silicon Dioxide (SiO2) with Hydrated Iron Oxides (FeO(OH)·nH2O)
Quartz with Mica (Gneissic or Pegmatitic origin)
Silicon Dioxide (SiO2) with Phyllosilicates (KAl2(AlSi3O10)(F,OH)2)
Milky Quartz (Water-Worn Pebble)
Silicon Dioxide (SiO2)
Yellow Quartz (Citrine/Quartzite Pebble)
Silicon Dioxide (SiO2)
Sodalite
Sodalite - Na8(Al6Si6O24)Cl2
Green Fluorite
Fluorite (Calcium Fluoride - CaF2)
Dolomite on Prehnite (Saddle-shaped Dolomite)
Dolomite [CaMg(CO3)2] on Prehnite [Ca2Al(AlSi3O10)(OH)2]
Rough Diamond
Diamond (pure Carbon, C)
Erythrite (or Lab-Grown Cobaltite/Cinnabar Analog)
Erythrite (Co3(AsO4)2·8H2O)
Chert (Jasper)
Silicon Dioxide (SiO2)
Milky Quartz (Water-Worn Pebble)
Quartz (Silicon Dioxide, SiO2)
Red Sandstone
Arenite (primarily Quartz with Hematite cement)
Biotite Schist
Biotite Schist
Yellow Quartz Pebble
SiO2 (Silicon Dioxide)
Sandstone
Sandstone (clastic sedimentary rock), primarily SiO2
Banded Agate
Agate (Cryptocrystalline variety of Quartz, SiO2)
Blue Calcite
Calcium Carbonate (CaCO3)
Quartz with Mica inclusion
Silicon Dioxide (SiO2) with Muscovite/Biotite inclusions
Sodalite
Sodalite (Na8Al6Si6O24Cl2)
Schist
Crystalline Schist (often containing Muscovite, Biotte, or Quartz)
Cubic Zirconia (as used in jewelry setting)
Zirconium dioxide (ZrO2)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Fuchsite
K(Al,Cr)2(AlSi3O10)(OH)2 (Chromium-rich Muscovite)
Rough Emerald
Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)
Chert / Flint Nodules in Limestone
Silicon Dioxide (SiO2) within Calcium Carbonate (CaCO3)
Honey Calcite
Calcium Carbonate (CaCO3)
Quartz (Peach/Orange variety)
Silicon Dioxide (SiO2)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Honey Calcite
Calcium Carbonate (CaCO3)
Schorl (Black Tourmaline)
Schorl (Sodium Iron Aluminum Borosilicate Hydroxide), NaFe3Al6(BO3)3Si6O18(OH)4
Green Fluorite
Fluorite (Calcium Fluoride, CaF2)
Rainbow Fluorite
Calcium Fluoride (CaF2)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese