Uncertain

Likely weathered granite or granitic gneiss

Granite; quartz–feldspar–mica aggregate (possibly foliated gneiss)

Likely green aventurine (quartz-rich rock)

Quartz-rich rock with possible fuchsite mica; composition cannot be confirmed from the photo

Polished banded agate (likely sardonyx/carnelian agate)

Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide color bands

Botryoidal calcite specimen

Calcite, CaCO₃, with possible dolomite or other carbonate matrix

Chert (flint), brown variety

Microcrystalline quartz (SiO₂)

Banded agate (likely polished/tumbled)

Agate, a banded variety of chalcedony (microcrystalline quartz, SiO₂)

Smoky quartz crystal

Quartz (SiO₂), likely smoky quartz

Clear quartz crystal

Quartz (silicon dioxide, SiO₂)

Likely weathered pebble or mineral fragment

Indeterminate; possibly quartz-rich stone, iron-stained feldspar, or a small chert fragment

Rounded metamorphic cobble, likely gneiss or amphibolite

Banding-free biotite–quartz–feldspar gneiss or amphibolite; exact identification requires testing

Chert or flint fragment

Microcrystalline quartz (SiO₂), likely chert

Tumbled honey-colored chalcedony (possibly yellow agate)

Microcrystalline quartz, SiO₂; chalcedony, potentially banded agate

Weathered chert (flint) pebble

Microcrystalline quartz (SiO₂), commonly called chert or flint

Rose quartz

Quartz, silicon dioxide (SiO₂), pink variety

Green aventurine (likely)

Quartz, SiO₂, with green fuchsite inclusions

Tumbled hawk’s eye (blue tiger’s eye)

Quartz (SiO₂) with parallel, crocidolite-derived fibrous inclusions

Tumbled brecciated jasper (likely)

Jasper, an opaque microcrystalline variety of quartz (SiO₂), with pale quartz/chalcedony veins

Green jade-like carved pendant or worry stone

Likely nephrite jade (tremolite–actinolite), but the image alone cannot confirm the material

Rutilated quartz beads

Quartz (SiO₂) with rutile (TiO₂) inclusions

Likely rose quartz

Quartz (SiO₂), variety rose quartz

Milky quartz (rough quartz crystal)

Quartz, silicon dioxide (SiO₂)

Likely polished quartz-rich stone or calcite specimen

Uncertain; possibly quartz (SiO₂) or calcite (CaCO₃)

Tumbled dark stone, likely labradorite or serpentine

Likely labradorite (plagioclase feldspar; approximately NaAlSi₃O₈–CaAl₂Si₂O₈) or serpentine-group mineral

Quartz-rich rock, likely quartzite or weathered sandstone

Quartzite (mostly SiO₂); possibly quartz arenite sandstone

Weathered quartz-rich rock fragment (possibly iron-stained quartzite)

Quartzite; primarily quartz (SiO₂), with iron-oxide staining and minor accessory minerals

Likely blue sapphire ring

Corundum (Al₂O₃), likely sapphire; surrounding stones may be diamonds or colored gems

Likely gray granitic rock

Granite or granodiorite; chiefly quartz, feldspar, and mica/amphibole

Rounded quartz-rich beach pebble

Likely milky quartz or quartzite (SiO₂)

Likely serpentinite

Serpentinite, composed mainly of serpentine-group minerals (e.g., antigorite, lizardite, or chrysotile)

Galena (likely)

Galena, lead sulfide (PbS)

Biotite mica

Biotite, a potassium-rich mica in the annite–phlogopite series; approximate formula K(Mg,Fe)₃AlSi₃O₁₀(F,OH)₂

White mica (likely muscovite)

Muscovite, KAl₂(AlSi₃O₁₀)(OH)₂

Milky quartz

Quartz, silicon dioxide (SiO₂)

Polished carnelian agate

Chalcedony, microcrystalline SiO₂; the reddish variety is commonly called carnelian

Pegmatite

Granitic pegmatite, likely quartz and feldspar with dark mica (biotite)

Gray chalcedony (possibly agate)

Microcrystalline quartz, SiO₂

Polished carnelian agate

Chalcedony, microcrystalline quartz (SiO₂), with iron-oxide color bands

Brown tumbled stone, likely smoky quartz

Quartz (SiO₂), possibly iron-stained or smoky quartz

Iron-rich sandstone or weathered ironstone fragment

Ferruginous sandstone; quartz (SiO₂) cemented or stained by iron oxides such as hematite/goethite

Red jasper (possible polished or dyed stone)

Jasper, an opaque microcrystalline variety of quartz (SiO₂)

Weathered garnet-bearing rock (possibly garnet schist)

Garnet-bearing mica schist; likely almandine garnet (Fe₃Al₂(SiO₄)₃) with mica and quartz

Rough rose quartz

Quartz (SiO₂), pink variety commonly called rose quartz