Anthropogenic Material

Possible weathered basalt or iron-rich volcanic stone

Fine-grained mafic rock, possibly basalt; exact identification requires testing

Quartz-rich metamorphic rock, likely quartzite

Quartzite, composed predominantly of quartz (SiO₂), with dark biotite, amphibole, or iron-oxide inclusions

Likely weathered igneous rock fragments

Indeterminate; possibly basaltic or granitic rock with quartz, feldspar, and dark mafic minerals

Iron-stained milky quartz vein

Quartz (SiO₂), with iron-oxide/hydroxide staining and minor dark inclusions

Polished/tumbled rhodonite-rich stone

Rhodonite (MnSiO₃), likely mixed with quartz and manganese oxides

White quartzite pebble

Quartzite; predominantly microcrystalline quartz (SiO₂)

Quartzite River Pebble

Quartzite (primarily SiO2)

Ruby in Zoisite (Anyolite) or possibly a dyed stone/agate

Anyolite (Ruby in green zoisite) or artificially altered chalcedony

Quartz (Chert/Flint variety)

Silicon Dioxide (SiO2)

Chert / Flint

Silicon dioxide (Microcrystalline Quartz, $SiO_2$)

Chondrite Meteorite

Stony Meteorite (Ordinary Chondrite)

Dalmatian jasper

Quartz-bearing alkali feldspar syenite/porphyritic igneous rock, commonly marketed as Dalmatian jasper

Polished kambaba jasper

Orbicular stromatolitic jasper; microcrystalline quartz (SiO₂) with chlorite/amphibole-rich inclusions

Milky Quartz Chip

Silicon Dioxide (SiO2)

Asphalt Pavement (with aggregate)

Asphalt concrete

Sandstone

Sedimentary rock composed mainly of quartz and feldspar

Sandstone

Clastic Sedimentary Rock

Polished unakite pebble

Unakite: epidote, pink orthoclase feldspar, and quartz

Sandstone or similar clastic rock

Arenite

Limestone or Sandstone Cobble

Sedimentary rock (Calcium carbonate or Quartz based)

Quartz Vein in River Siltstone

Crystalline Quartz (SiO2) in Siliclastic Matrix

Pumice or Scoria

Vesicular volcanic rock

Sandstone

Sandstone (Quartz-rich Arenite / SiO2)

Iron-rich laterite or limonite/goethite concretion

Hydrated iron oxides, chiefly goethite (α-FeO(OH)) and limonite (FeO(OH)·nH₂O)

Chalcedony (Chert/Flint)

Silicon Dioxide (SiO2)

Yellow jasper / iron-rich chert

Microcrystalline quartz (SiO₂), commonly colored by iron oxides

Blue-green cabochon, likely chalcedony or treated glass imitation

Cryptocrystalline quartz (chalcedony/possibly chrysoprase); identification uncertain from image

Petrified Wood

Silicified Wood (SiO2)

Asphalt (Bituminous Rock)

Natural bitumen or Bituminous limestone/sandstone

Dyed tumbled stone, likely chalcedony or quartz

Microcrystalline quartz (SiO₂), probably dyed magenta

Coquina

Biogenic Limestone (Calcium Carbonate, CaCO3)

Chert

Microcrystalline Quartz (SiO2)

Chert pebble

Microcrystalline silica (SiO2)

Amber-colored bead earrings

Likely amber (fossilized tree resin); material cannot be confirmed from the image

Turquoise cabochon or turquoise-bearing material

Turquoise, hydrated copper aluminum phosphate — CuAl₆(PO₄)₄(OH)₈·4H₂O

Natural turquoise-bearing rock

Turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O, likely in a limonite or host-rock matrix

Polished turquoise-colored stone, likely chrysoprase or dyed agate

Uncertain; possible chalcedony (microcrystalline SiO₂) or turquoise (hydrous copper aluminum phosphate)

Tumbled ruby in matrix

Corundum (Al₂O₃), commonly with mica, calcite, or other matrix minerals

Polished ocean jasper (orbicular jasper), probable

Silicified orbicular rhyolite; chiefly microcrystalline quartz (SiO₂)

Clear crystal-bead bracelet, possibly quartz

Unidentified transparent mineral beads; quartz (SiO₂) is one possibility

Jasper

Silicon dioxide (SiO2)

Fossilized Shark Tooth

Chondrichthyes tooth