Identify any rockfrom a photo.

Weathered feldspar-rich rock, possibly granite or pegmatite

Quartz–feldspar rock; exact identification is uncertain from the photo

Likely malachite-bearing copper ore

Possibly malachite (Cu₂CO₃(OH)₂) with dark copper-bearing host rock; identification is uncertain from the image

Rough turquoise

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

Milky quartz

Quartz (silicon dioxide, SiO₂)

Mica-rich pegmatite (likely muscovite with quartz and feldspar)

Granitic pegmatite; chiefly muscovite mica, quartz (SiO₂), and feldspar

Pegmatitic quartz–feldspar rock

Granitic pegmatite, composed mainly of quartz (SiO₂) and feldspar; mica may also be present

Chalcedony (possibly agate)

Microcrystalline quartz, SiO₂; agate is banded chalcedony

Quartz–mica-rich metamorphic rock (likely mica schist)

Quartz–muscovite ± biotite schist; exact identification requires examination of a fresh surface

Black Onyx (in jewelry setting)

Silicon Dioxide (SiO2)

Rough limestone or dolostone outcrop

Carbonate rock, mainly calcite (CaCO₃) and/or dolomite [CaMg(CO₃)₂]

Rounded speckled granite pebble

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

Banded gneiss pebble

Foliated gneiss; likely quartz- and feldspar-rich, with dark mica or amphibole bands