Not A Rock (Man Made Origin)

Sandstone

Arenite (composed primarily of SiO2)

Iron-stained quartz pebble

Quartz (SiO₂), likely stained or coated with iron oxides

Granite

Phaneritic Plutonic Felsic Rock

Granite

Granite (Phaneritic igneous rock)

Dark mafic rock, possibly basalt or altered gabbro

Basaltic rock; commonly composed of plagioclase feldspar, pyroxene, and possibly olivine or iron oxides

Granite

Intrusive Igneous Rock (Granitic)

Turquoise

Hydrated copper aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O

Sandstone (Ferruginous)

Arenite (SiO2 with Fe2O3 inclusions)

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Colorless faceted gemstone, likely glass or cubic zirconia

Uncertain; possible cubic zirconia (ZrO₂) or quartz (SiO₂), but the image may show a man-made simulant

Colorless faceted quartz-like gemstone

Likely quartz (SiO₂), though the appearance may also indicate man-made glass or cubic zirconia

Quartz Pebble

Silicon Dioxide (SiO2)

Dark metamorphic cobble, likely slate or phyllite

Foliated metamorphic rock, probably carbonaceous slate/phyllite; exact identification requires testing

Obsidian

Volcanic Glass (Amorphous Silicon Dioxide)

Banded Rock (likely Quartz-rich)

Uncertain, likely a Metamorphic Rock (e.g., Gneiss or Schist) with prominent Quartz and other minerals

Small quartz-rich rock fragment

Likely quartz (SiO₂), possibly a pale granite or feldspar-bearing fragment

Fossil Coral

Scleractinia (Stony Coral) fossil

Colorless faceted gemstone, likely glass or cubic zirconia

Uncertain; possible cubic zirconia (zirconium dioxide, ZrO₂) or synthetic glass

Possible iron meteorite

Fe–Ni iron meteorite, possibly an ordinary chondrite or weathered iron-rich specimen

Emerald

Beryl (Be3Al2(SiO3)6) with Chromium and/or Vanadium impurities

Possible iron meteorite

Iron–nickel meteorite, commonly kamacite-taenite (Fe-Ni alloy)

Dark brown mineral fragments, possibly garnet or iron-rich rock

Indeterminate from image; possible almandine garnet (Fe₃Al₂Si₃O₁₂) or limonite-rich material

Granite pebble

Granite, a coarse-grained felsic intrusive igneous rock composed chiefly of quartz, feldspar, and mica

Likely weathered quartz-rich rock, possibly granite or gneiss

Granite–gneiss assemblage; chiefly quartz, feldspar, and dark mica/amphibole

Quartzite

Metamorphic Quartz Rock (SiO2)

Opal ring

Precious opal, hydrated amorphous silica (SiO₂·nH₂O), set in a metal ring

Milky quartz-bearing rock, likely quartzite or silicified limestone

Quartz (SiO₂), possibly in a quartzite or chalcedony-rich matrix

Sandstone (Yellow/Tan)

Clastic sedimentary rock (primarily SiO2 with iron oxide staining)

Sandstone

Clastic Sedimentary Rock

Sandstone

Arenite (mostly SiO2)

Gastropod Fossil (Steinkern)

Class Gastropoda (internal mold)

Black Diamond (Carbonado)

Carbonado (Polycrystalline Diamond)

Likely quartz-rich stone, possibly milky quartz

Quartz (silicon dioxide, SiO₂)

Lapis Lazuli (Tumbled)

Lazurite-dominated contact metamorphic rock

Likely gray granite or gneiss fragment

Granite: quartz, feldspar, and mica; possibly banded gneiss if foliation is present

Granite

Felsic intrusive igneous rock

Lapis Lazuli

Na8[Al6Si6O24]Sn (Lazurite-rich metamorphic rock)

Bauxite

Bauxite (principal ore of aluminum, primarily Al(OH)3)

Likely opal-inlay cross pendant

Opal (hydrated amorphous silica, SiO₂·nH₂O); central red stone is unidentified

Likely weathered sandstone or iron-rich volcanic rock

Indeterminate from photograph; probable ferruginous sandstone, possibly altered volcanic rock

Lapis Lazuli

Lazurite-dominant Metamorphic Rock (complex aluminosilicate)

Sandstone

Arenite (composed primarily of SiO2)