Identify any rockfrom a photo.

Basalt pebble

Basalt; chiefly plagioclase feldspar, pyroxene, and commonly olivine or iron oxides

Rounded basalt cobble

Basalt; predominantly plagioclase, pyroxene, and commonly olivine

Weathered granite or granitic rock

Coarse-grained granitic rock, likely granite or granodiorite; identification is provisional from the photograph

Banded gneiss (probable)

Gneiss, commonly quartz–feldspar–mica bearing

Iron-rich meteorite (probable stony-iron or weathered iron meteorite)

Unclassified meteorite; likely Fe–Ni metal with silicate minerals

Polished labradorite cabochon

Labradorite, plagioclase feldspar; approximately NaAlSi₃O₈–CaAl₂Si₂O₈

Vesicular basalt (likely scoriaceous basalt)

Mafic volcanic rock, chiefly plagioclase, pyroxene, and olivine; commonly iron-rich volcanic glass

Black-and-white tourmaline granite (likely polished stone)

Tourmaline-bearing granite, chiefly quartz, feldspar, mica, and black schorl tourmaline

Tumbled granite or granitic gneiss

Granite: quartz, feldspar, and mica; possibly foliated gneiss

Tumbled feldspar-rich rock, possibly moonstone-bearing granite

Plagioclase feldspar (albite–oligoclase), with probable quartz and dark mica/amphibole; exact identification requires testing

Possible iron-rich meteorite or metallic sulfide-bearing rock

Unconfirmed; candidates include stony-iron meteorite, iron meteorite, or pyrite-bearing terrestrial rock

Serpentine-rich metamorphic rock (probable serpentinite)

Serpentinite; chiefly serpentine-group minerals (antigorite, lizardite, or chrysotile), commonly with magnetite and chromite