Quartz
Silicon Dioxide (SiO2)
Category
Browse mineral like byproduct specimens identified by the Rock Identifier community.
Quartz
Silicon Dioxide (SiO2)
Limonite (Ironstone)
FeO(OH)qn H2O
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Sandstone
Arenite (primarily composed of SiO2)
Sandstone (Banded)
Arenite (primarily SiO2)
Fossil-bearing rock, possibly a fossiliferous sandstone or limestone
Unidentified sedimentary matrix with fossil impressions; exact fossil and rock cannot be determined from the image
Gneiss
Gneiss
Geode (Unopened)
Chalcedony/Quartz Geode (SiO2)
Muscovite Mica
Muscovite (KAl2(AlSi3O10)(OH)2)
Fossilized Echinoid
Echinoidea
Chrysocolla on Matrix
Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4·nH2O
Granite
Phaneritic felsic intrusive igneous rock
Quartz with inclusions (likely Tourmaline or Biotite)
Silicon Dioxide (SiO2)
Proustite
Proustite (Ag3AsS3)
Limonite Concretion
Limonite (FeO(OH)·nH2O) Pseudomorph
Green glass-like mineral specimen, likely fluorite
Fluorite (calcium fluoride, CaF₂), if natural; appearance may also indicate colored glass
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals like Antigorite, Lizardite, and Chrysotile)
Sandstone
Sandstone (clastic sedimentary rock)
Greenschist
Chlorite Schist
Arsenopyrite
Arsenopyrite (FeAsS)
Red heart-shaped glass bead in a wire-wrapped jewelry charm
Likely colored glass (amorphous silica-based material); the image does not show an identifiable geological specimen
Banded Gneiss
Banded Gneiss (Metamorphic Rock)
Gneiss
Gneiss (High-grade metamorphic rock)
Almandine Garnet
Fe3Al2(SiO4)3
Muscovite Mica
Muscovite (KAl2(AlSi3O10)(OH)2)
Quartz Geode Fragment
Silicon Dioxide (SiO2) in a Sedimentary Host
Lepidolite
K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2
Vanadinite
Pb5(VO4)3Cl
Limonite with Ironstone
Limonite (hydrated iron(III) oxide-hydroxides), FeO(OH)·nH2O
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)
Mahogany Obsidian
Volcanic glass (SiO2 with Hematite or Magnetite inclusions)
Obsidian
Volcanic Glass (SiO2)
Man-made Synthetic Material (Costume Faux Fur)
Synthetic Polymer (Polyester/Acrylic)
Sandstone (Quartzose)
Arenite (SiO2 based typically)
Calcite (Yellow/Orange variety - sometimes called Honey Calcite)
Calcite
Granite
Granite
Halite (Rock Salt)
Halite (Sodium Chloride, NaCl)
Sandstone Concretion
Clastic Sedimentary Concretion (primarily SiO2 with Fe2O3 cement)
Blue Quartz
Silicon Dioxide (SiO2) with inclusions
Limonite
Hydrated iron oxide-hydroxide, FeO(OH)·nH2O
Limonite
FeO(OH)•nH2O
Orthoclase Feldspar
KAlSi3O8 (Potassium Aluminum Silicate)