Sedimentary (Processed Mineral Product)

Slag

Anthropogenic Vitrification Product / Silicate Slag

Acrylic or Resin (Synthetic Imitation)

Polymethyl Methacrylate (PMMA) or Polyepoxide

Shale

Shale (fine-grained clastic sedimentary rock)

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Tumbled tiger’s-eye

Quartz variety, chiefly fibrous chalcedony pseudomorph after crocidolite; SiO₂

Hematite

Iron Oxide (Fe2O3)

Tumbled copper-bearing rock, likely cuprite-rich matrix

Cuprite (Cu₂O) with native copper and iron-oxide matrix; visual identification is provisional

Tumbled sodalite

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂

Quartz geode

Quartz (SiO₂), likely drusy/microcrystalline quartz lining a geode cavity

White quartz pebble (likely milky quartz)

Quartz, silicon dioxide (SiO₂)

Tumbled chalcedony or quartz

Microcrystalline silica, SiO₂ (likely chalcedony; possibly milky quartz)

Blue-green turquoise-like tumbled stone

Turquoise, hydrous copper aluminum phosphate: CuAl₆(PO₄)₄(OH)₈·4H₂O

Quartz Pebble

Silicon Dioxide (SiO2)

Sea Glass

Amorphous silicon dioxide (Man-made glass weathered by nature)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Tiger's Eye

Silicified Crocidolite Pseudomorph (SiO2 with iron oxides)

Shale

Sedimentary rock composed of clay minerals and quartz

Red Sandstone

Arenite (SiO2 with Fe2O3)

Greenstone, likely serpentinite

Serpentinite; chiefly serpentine-group minerals (Mg₃Si₂O₅(OH)₄), possibly with magnetite and chlorite

Black tourmaline pendant

Schorl tourmaline, NaFe3Al6(BO3)3Si6O18(OH)4

Polished red granite or rhyolite pebble

Likely pink/red granite, composed chiefly of quartz, alkali feldspar, and mica; exact identification requires testing

Blue gemstone ring, likely blue topaz or synthetic blue spinel

Likely topaz (Al₂SiO₄(F,OH)₂) or synthetic spinel (MgAl₂O₄); identification is uncertain from the image

Diamond ring

Diamond (crystalline carbon, C)

Weathered iron-rich rock, possibly laterite or altered basalt

Probable ferruginous basalt/lat eritic material; exact identification requires testing

Chert (Flint)

Silicon Dioxide (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Weathered granitic rock fragment

Likely granite or granodiorite, composed mainly of quartz, feldspar, and mica

Carved pale green jade-like pendant

Likely nephrite jade (tremolite–actinolite amphibole); possibly serpentine or treated aventurine

Carved lavender chalcedony (likely agate) animal figurine

Microcrystalline quartz, SiO₂; probable chalcedony or pale lavender agate

River Pebble

Polished Rock Fragment

Goethite

Goethite (α-FeO(OH))

Polished pink halite (Himalayan salt)

Halite (sodium chloride, NaCl)

Weathered quartz-rich rock, possibly quartzite or silicified breccia

Quartzite (predominantly SiO₂); exact identification requires a fresh surface and tests

Native copper-bearing sulfide specimen

Likely chalcopyrite (CuFeS₂), possibly with native copper and iron oxides

Likely tumbled yellow-orange mineral or glassy stone

Indeterminate from photograph; possibilities include yellow jasper, calcite, agate, or dyed quartz

Quartz on Sandstone

Silicon Dioxide (SiO2) in Lithic Sandstone

Iron-rich lateritic rock / weathered ironstone

Ferruginous laterite, commonly hematite–goethite-rich (Fe₂O₃–FeO(OH))

Green Calcite

Calcite (Calcium Carbonate, CaCO3)

Milky quartz in weathered host rock

Quartz, silicon dioxide (SiO₂), likely with iron-stained feldspar or altered matrix

Milky quartz

Quartz (silicon dioxide, SiO₂)