All rocks & minerals

Pink faceted gemstone, possibly tourmaline

Unidentified faceted mineral; pink tourmaline (elbaite, Na(Li₁.₅Al₁.₅)Al₆(Si₆O₁₈)(BO₃)₃(OH)₄) is one possibility

Blue topaz (possible)

Topaz, Al₂SiO₄(F,OH)₂

Possible blue sapphire

Corundum (Al₂O₃), possibly blue sapphire

Mixed polished stone and mineral collection

Several small, tumbled specimens; individual species cannot be identified reliably from the image

Small polished pink-and-white pebble, possibly quartz or feldspar

Undetermined; likely a quartz- or feldspar-rich silicate

Rainbow-coated amethyst (likely treated quartz)

Quartz, SiO₂; purple color from iron-related defects. The iridescent surface appears artificially coated, often with a titanium-based film.

Black tourmaline (schorl) in matrix

Schorl, NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

Granite

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

Likely mica-rich schist

Mica schist, probably muscovite- and/or biotite-bearing; exact identification requires closer examination

Fossil-bearing rock, possibly a fossiliferous sandstone or limestone

Unidentified sedimentary matrix with fossil impressions; exact fossil and rock cannot be determined from the image

Weathered porphyritic volcanic rock, possibly andesite

Porphyritic andesite (tentative; exact identification requires testing)

Tumbled red granite

Granite, chiefly quartz, feldspar, and mica

Likely rough garnet-bearing rock

Possibly garnetiferous schist or gneiss; identification is uncertain from the photo

Likely quartz-rich metamorphic pebble

Possibly quartzite; exact identification is uncertain from the photo

Small water-worn pebble, likely quartz-rich stone

Unidentified quartz-rich lithic pebble; precise identification is not possible from the image

Milky quartz

Quartz (silicon dioxide, SiO₂)

Rounded quartz-rich pebble, likely quartzite

Quartzite (predominantly silicon dioxide, SiO₂)

Milky quartz

Quartz (silicon dioxide, SiO₂)

Quartzite pebble

Quartzite, composed predominantly of quartz (SiO₂)

Water-worn sandstone pebble

Quartz-rich sandstone (composition and exact subtype uncertain from image)

Likely amphibolite

Amphibolite, composed chiefly of hornblende and plagioclase

Quartz-rich river pebble

Likely quartz-rich granitic rock; mainly quartz (SiO₂), with possible feldspar and mica

Granite (likely), hand-sized rough specimen

Granite; a coarse-grained rock composed chiefly of quartz, feldspar, and dark mica or amphibole

Calcite (honey calcite)

Calcite, calcium carbonate (CaCO₃)

Milky quartz

Quartz (SiO₂)

Hollow geode-like mineral concretion

Likely a quartz/chalcedony-lined concretion; exact identification requires examining the interior and testing the material

Quartzite pebble

Quartzite, composed predominantly of recrystallized quartz (SiO₂)

Vesicular basalt (possibly scoriaceous basalt)

Vesicular basalt; chiefly plagioclase, pyroxene, and iron-rich oxides

Dark igneous rock with white feldspar/quartz patches

Likely porphyritic basalt or andesite; white patches may be plagioclase feldspar or quartz

Weathered quartz-rich pebble

Likely quartzite or quartz-rich sandstone; exact identification is uncertain from the photo

Diamond (or Cubic Zirconia / Rhinestones)

Carbon (C) or Zirconium dioxide (ZrO2)

Rounded river pebble, likely quartz-rich sandstone

Quartz-rich sandstone (tentative; exact identification is limited from the image)

Rounded quartzite pebble

Quartzite, composed predominantly of quartz (SiO₂)

Fossiliferous limestone

Calcite-rich limestone (predominantly CaCO₃), with possible fossil fragments

Sandstone (Cut Dimension Stone)

Arenite / Quartzose Sandstone (primarily SiO2)

Possible iron-rich meteorite fragment

Unclassified suspected meteorite; composition cannot be determined from the photograph

Quartzite cobble (probable)

Quartzite, composed predominantly of recrystallized quartz (SiO₂)

Pegmatite

Granitic pegmatite, composed mainly of quartz and feldspar with possible mica

Pumice

Pumice, vesicular volcanic glass, commonly rhyolitic to dacitic in composition

Pegmatitic granite (quartz–feldspar–mica rock)

Granitic pegmatite; chiefly quartz (SiO₂), potassium feldspar and plagioclase, with dark mica such as biotite

Granite

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

Brecciated jasper

Iron-oxide-rich jasper (microcrystalline quartz, SiO₂), cut by a quartz- or calcite-rich vein