Identify any rockfrom a photo.

Polished turquoise (likely stabilized)

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

Polished turquoise cabochon

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

Possible hematite-bearing pebble

Hematite, Fe₂O₃, possibly mixed with magnetite or iron-rich matrix

Rounded dark pebble, likely basalt or weathered mafic rock

Basalt; predominantly plagioclase feldspar and pyroxene, possibly olivine

Black basalt pebble

Basalt; fine-grained mafic volcanic rock, chiefly plagioclase and pyroxene with possible olivine

Quartz-rich rock, possibly chrysoprase/chalcedony

Microcrystalline quartz (SiO₂), with iron-oxide staining and green inclusions; exact identification requires testing

Vesicular basalt (likely weathered basalt)

Basalt; primarily plagioclase, clinopyroxene, and Fe-Ti oxides

Likely mica-rich schist

Biotite–quartz–feldspar schist (tentative)

Tumbled quartz (rock crystal)

Quartz, silicon dioxide (SiO₂)

Gneiss (likely granitic gneiss)

Foliated quartz–feldspar gneiss, commonly derived from granite

Weathered granitic rock (likely granite or granodiorite)

Granite–granodiorite; chiefly quartz, feldspar, and biotite/amphibole

Clear quartz crystal (likely milky/included quartz)

Quartz, silicon dioxide (SiO₂)