Sandstone
Sandstone (arenite is a more specific geological term for a clean sandstone, while wacke refers to a dirty sandstone with significant matrix)
Category
Browse tektite (natural glass) specimens identified by the Rock Identifier community.
Sandstone
Sandstone (arenite is a more specific geological term for a clean sandstone, while wacke refers to a dirty sandstone with significant matrix)
Sandstone
Quartz Arenite (a common type of sandstone, given the appearance), Arkose, Greywacke (depending on mineralogy)
Quartz (River-worn Pebble)
Quartz (SiO2)
Chalcedony (or a variety of Chalcedony, likely Agate or Jasper)
Chalcedony (SiO₂)
Sunstone and Green Aventurine
Sunstone: (Ca,Na)[(Al,Si)2Si2O8] (Plagioclase Feldspar Group); Green Aventurine: SiO2 (Quartz)
Micaceous Rock (likely Muscovite Schist/Gneiss or a Muscovite-rich Specimen)
Predominantly Muscovite (KAl2(AlSi3O10)(F,OH)2), often found in rocks like Muscovite Schist or Muscovite Gneiss.
Quartz (various varieties)
SiO₂ (Silicon Dioxide)
Chert / Flint
Chert (varieties include Flint)
Quartz (River Pebble)
Quartz (SiO₂ - Silicon Dioxide)
Diamond
Diamond (pure carbon; C)
Black Tourmaline
Schorl (Na(Fe2+)_{3}Al_{6} (BO_{3})_{3} (Si_{6}O_{18})(OH)_{4})
Quartz (likely Jasper or Chert variety)
Quartz (SiO₂)
Pink Stained Rock (Likely Quartzite or Sandstone with Iron Oxide Staining)
Quartzite (metamorphic) or Sandstone (sedimentary); coloration likely due to hematite or other iron oxides.
Slag (Industrial Glassy Byproduct)
Ferro-silicate Slag
Black Tourmaline (Schorl)
Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)
Peridot (likely, given the color and bead form)
Olivine, variety Peridot (Mg,Fe)2SiO4
Quartz
Quartz (SiO2 - Silicon Dioxide)
Green Aventurine
Aventurine Quartz (SiO2 with fuchsite inclusions)
Sandstone
Sandstone (lithified arenite/wacke)
Peridot and Citrine Gemstones (in a ring setting)
Peridot (Olivine: (Mg,Fe)2SiO4), Citrine (Quartz: SiO2)
Sandstone
Sandstone (Clastic Sedimentary Rock)
Rhodonite beads (possibly dyed or treated, or lower quality Rhodonite)
Manganese inosilicate, (Mn,Fe,Mg,Ca)SiO3
Aventurine
Aventurine Quartz (SiO2 with inclusions)
Sandstone (Pebble/Conglomerate fragment)
Sandstone (clastic sedimentary rock)
Amber (Black)
Amber (succinite, retinite, etc., specifically, heavily included/dark varieties)
Amethyst
Quartz variety; chemical formula: SiO₂ (silicon dioxide) with Fe³⁺ impurities
Smoky Quartz
SiO2 (Silicon Dioxide)
Aquamarine and clear quartz
Aquamarine (Be3Al2Si6O18), Quartz (SiO2)
Sandstone (likely a river or beach pebble)
Sandstone (a clastic sedimentary rock)
Black Tourmaline (Schorl)
Schorl (Na(Fe^2+)3Al6(Si6O18)(BO3)3)(OH)3(OH))
Agate
Agate (a cryptocrystalline variety of Quartz, SiO₂)
Green Agate
Silicon dioxide (SiO₂)
Smoky Quartz
Smoky Quartz (SiO2)
Quartz (Rock Crystal) with minor impurities
Quartz (SiO2)
Agate
Agate (a variety of Chalcedony, SiO2)
Agate (or Banded Agate)
Agate (a variety of Chalcedony, which is a cryptocrystalline form of Quartz); Chemical Formula: SiO₂ (Silicon Dioxide)
Clear Quartz (beads in a bracelet)
Quartz (SiO2)
Flint
Chert (a form of cryptocrystalline quartz, chemical formula SiO₂)
Hematite
Hematite (Fe2O3)
Banded Chert or Chert with Quartz Veins
Chert (SiO2)
Quartz (variety of colors)
SiO2 (Silicon Dioxide)
Cobalt Glass Slug (Man-made Glass)
Amorphous Silica with Cobalt Oxide (SiO2 + CoO)