All rocks & minerals

Polished brown agate or chalcedony pendant

Microcrystalline quartz (SiO₂), likely brown chalcedony/agate

Sandstone

Quartz-rich clastic sandstone; exact variety cannot be determined from the image

Tumbled honey-colored chalcedony (possibly yellow agate)

Microcrystalline quartz, SiO₂; chalcedony, potentially banded agate

Tumbled smoky quartz

Quartz (SiO₂), likely smoky variety

Polished banded agate

Agate, microcrystalline quartz (SiO₂; chiefly chalcedony)

Tumbled rose quartz

Quartz, SiO₂; pink variety known as rose quartz

Tumbled rose quartz

Quartz, SiO₂; rose-colored variety commonly called rose quartz

Milky quartz pebble

Quartz (silicon dioxide, SiO₂)

Tumbled chalcedony (possibly peach agate)

Microcrystalline quartz, SiO₂; agate is banded chalcedony

Tumbled rose quartz

Quartz, SiO₂ (pink variety)

Tumbled carnelian (orange-brown chalcedony)

Chalcedony, microcrystalline quartz (SiO₂); carnelian is its iron-colored variety

Tumbled honey-brown chalcedony, possibly carnelian

Microcrystalline quartz (SiO₂); chalcedony, with carnelian referring to orange-red varieties

Gray chert (flint) nodule

Microcrystalline quartz (SiO₂), likely chert

Tumbled chalcedony (likely agate)

Chalcedony, microcrystalline quartz (SiO₂); banding is not clearly visible to confirm agate

Polished carnelian agate

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

Tumbled banded agate

Agate, a microcrystalline variety of quartz (SiO₂)

Tumbled blue-gray pebble, likely blue aventurine or quartzite

Quartz-rich rock; exact identification is uncertain from appearance alone

Likely gneiss (rounded river-worn pebble)

Foliated quartz–feldspar gneiss, with mica and possibly amphibole

Tumbled amber

Fossilized tree resin (amber; composition varies, commonly C₁₀H₁₆O)

Polished brown jasper pebble

Jasper, an opaque, microcrystalline variety of quartz (SiO₂)

Polished smoky quartz

Quartz (SiO₂), smoky variety

Tumbled cream-colored stone, likely calcite

Likely calcite (CaCO₃); visual identification is uncertain

White quartz pebble

Quartz (SiO₂), likely milky quartz

Polished brown-green stone, likely jade or serpentine

Undetermined; possible jadeite (NaAlSi₂O₆), nephrite (Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂), or serpentine-group mineral

Tumbled agate (likely)

Microcrystalline quartz, SiO₂; agate is banded chalcedony

Dalmatian jasper (often sold as Dalmatian stone)

Quartz- and feldspar-rich porphyritic volcanic rock; the trade name “Dalmatian jasper” is not a formal mineral species

Tumbled peach agate

Microcrystalline quartz (SiO₂), chalcedony variety; likely agate

Tumbled chalcedony (likely agate)

Microcrystalline quartz, SiO₂; chalcedony, possibly banded agate

Likely beach-worn pebbles

Lithified rock fragments; exact rock type cannot be determined from the photo

Rounded beach pebbles, likely quartz-rich

Unidentified lithic pebbles; possibly quartzite or quartz-rich sandstone

Tumbled milky quartz

Quartz (SiO₂)

Tumbled white stone, likely milky quartz

Quartz (SiO₂), probable; identification is uncertain from the photo alone

Black obsidian (likely)

Volcanic glass, chiefly silica-rich rhyolitic composition (SiO₂-rich); exact identification cannot be confirmed from the image

Milky quartz with iron staining

Quartz, silicon dioxide (SiO₂)

Red jasper pebble

Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored mainly by iron oxides

Carnelian (Chalcedony Pebble)

Silicon Dioxide (SiO2 with iron impurities)

Small gray rock fragment, possibly limestone or marl

Undetermined carbonate-rich sedimentary rock; composition cannot be confirmed visually

Likely basalt (dark volcanic rock)

Basalt; a fine-grained mafic rock composed chiefly of plagioclase and pyroxene, commonly with olivine

Likely limestone

Calcite-rich limestone (primarily CaCO₃)

Dark mafic rock fragment, possibly basalt

Basalt (tentative; image alone is insufficient for a definitive identification)

Vesicular basalt (dark volcanic rock)

Basalt, a fine-grained mafic volcanic rock; exact identification is uncertain from the image

Dark, coarse-grained rock (likely basalt)

Possibly basalt, composed chiefly of plagioclase and pyroxene; the image is not clear enough for a confident identification.