Chevron Amethyst
Silicon dioxide, SiO2 (Quartz variety)
Category
Browse organic (often found by beachcombers) specimens identified by the Rock Identifier community.
Chevron Amethyst
Silicon dioxide, SiO2 (Quartz variety)
Graywacke (River Cobble)
Graywacke (Lithic Sandstone)
River Stone (likely Basalt or Greywacke)
Basalt with mineral veining
Eclogite
Eclogite (composed primarily of Omphacite and Pyrope Garnet)
Sandstone (with potential trace fossils)
Clastic sedimentary rock (primarily SiO2)
Raw Emerald
Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)
Porphyritic Rhyolite (Cookie Stone)
Porphyritic Rhyolite (SiO2, with phenocrysts)
Jade (likely Nephrite Jade based on appearance)
Nephrite (a variety of actinolite, Ca2(Mg,Fe)5Si8O22(OH)2)
Sandstone Concretion
Sandstone (Sedimentary rock, mostly SiO2)
Opalite
Synthetic Opalite (Man-made glass)
Galena
Lead(II) sulfide (PbS)
Sandstone Concretion
Septarian or Carbonate-cemented Sandstone Concretion
Quartz / Chert
Silicon Dioxide (SiO2)
Chert with Desert Varnish
Cryptocrystalline Quartz (SiO2) with Manganese/Iron oxide coating
Serpentinite
Serpentinite (composed primarily of Serpentine minerals: Mg3Si2O5(OH)4)
Quartzite
Quartzite (SiO2)
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) within Matrix
Quartzite
Quartzite (chiefly SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Quartz Vein in Host Rock
Silicon Dioxide (SiO2)
Pink Tourmaline in Quartz Matrix
Elbaite (Na(Li,Al)3Al6(BO3)3Si6O18(OH)4) with Quartz (SiO2)
Quartzite
Quartzite (SiO2-rich metamorphic rock)
Quartzite
Metamorphosed Sandstone (SiO2)
Honey Calcite
Calcite (Calcium Carbonate, CaCO3)
Quartzite
Quartzite (SiO2)
Quartzite
Quartzite (SiO2)
Quartzite with Chlorite and Iron Staining
Quartzite (SiO2) with Chlorite (Mg,Fe)3(Si,Al)4O10(OH)2
Greenstone (Epidote/Chlorite-rich Metabasalt)
Greenschist / Epidosite (Ca2(Al,Fe)3(SiO4)3(OH))
Quartzite
Quartzite (primarily SiO2)
Nobby Hematite (Iron Ore)
Hematite (Fe2O3)
Topaz
Topaz (Al2SiO4(F,OH)2)
Lepidolite
K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2
Granite Cobble
Granite
Agate
SiO2
Diorite (Salt and Pepper Rock)
Diorite
Sandstone (Arkose)
Arkose Sandstone (principally SiO2 with Feldspar)
Yellow Quartzite (Iron-Stained)
Quartzite (primarily SiO2 with iron oxide impurities)
Quartzite
Quartzite (SiO2)
Quartzite pebble
Quartzite (SiO2)
Ferruginous Quartzite (Red Chert/Jasper-like)
Metamorphosed Quartzite with Hematite inclusions (SiO2 + Fe2O3)
Quartzite
Quartzite (SiO2)