All rocks & minerals

Smoky quartz crystal

Quartz (SiO₂), likely smoky quartz

Polished gray chalcedony (likely agate)

Microcrystalline quartz, SiO₂; chalcedony, possibly banded agate

Likely iron-stained quartz or quartzite fragment

Quartz (SiO₂), possibly ferruginous quartzite; identification is uncertain from the image

Tumbled blue lace agate

Banded chalcedony, a microcrystalline variety of quartz (SiO₂)

Tumbled yellow-green stone, possibly serpentine

Serpentine-group minerals, commonly antigorite or lizardite; identification from the image is uncertain

Tumbled rhodonite

Rhodonite, (Mn,Fe,Mg,Ca)SiO₃

Fossil coral

Fossilized colonial coral, likely a tabulate or rugose coral; exact genus cannot be determined from the photo

Polished chrysocolla specimen

Chrysocolla, a hydrated copper silicate; commonly intergrown with quartz, malachite, or other copper minerals

Fossiliferous limestone (likely coral or shell-bearing limestone)

Calcite-rich bioclastic limestone, chiefly CaCO₃

Mica (likely muscovite)

Muscovite, KAl₂(AlSi₃O₁₀)(OH)₂

Quartz crystal (likely clear quartz)

Quartz, silicon dioxide (SiO₂)

Rough ruby-bearing rock (possible ruby in matrix)

Corundum (Al₂O₃), possibly ruby; the dark matrix is not identifiable from this image

Ruby-bearing rock (likely ruby in zoisite)

Corundum (ruby, Al₂O₃) in a zoisite-rich matrix; exact identification is uncertain from the photograph

Tumbled white stone, possibly milky quartz

Likely quartz (SiO₂); identification is uncertain from the photo

White marble religious statuette

Marble, predominantly recrystallized calcite (CaCO₃); the image cannot establish the exact stone or whether it is marble rather than another white stone.

Hematite (hematite beads or tiles)

Hematite, α‑Fe₂O₃

Tumbled pink zebra jasper

Likely pink-and-black banded marble or jasper; exact identification is uncertain from the image

Kiwi jasper (sesame jasper)

Trade name for a polished, mottled rock, commonly a mix of quartz/chalcedony and dark amphibole or other inclusions; exact composition cannot be confirmed from the photo.

Dendritic limestone (likely manganese-oxide dendrites)

Calcite-rich limestone with manganese-oxide dendritic coatings or inclusions

Pyrite-bearing schist

Quartz–mica schist with disseminated pyrite (FeS₂), possibly other iron sulfides

Iron-stained quartz-rich rock

Likely quartzite with hematite/goethite staining; exact identification requires testing

Dark, fine-grained rock fragment; possibly basalt

Undetermined; basalt is a tentative identification from the image

Likely slate

Slate, a fine-grained metamorphic rock composed mainly of mica-group minerals, quartz, and chlorite

Likely fine-grained greenstone

Greenstone, typically metamorphosed mafic volcanic rock (metabasalt; commonly chlorite- and actinolite-bearing)

Quartz-rich pegmatite

Granitic pegmatite, composed mainly of quartz (SiO₂) and feldspar, with dark mica or other accessory minerals

Likely basalt or andesite fragments

Fine-grained volcanic rock, likely basalt (plagioclase and pyroxene, sometimes olivine); exact identification requires testing

Weathered sandstone slab

Quartz-rich sandstone; exact composition cannot be confirmed from the image

Polished rainbow jasper (likely orbicular jasper)

Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored by iron and other mineral inclusions

Iron-stained quartzite

Quartzite, composed predominantly of quartz (SiO₂), with iron-oxide staining

Polished banded agate

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

Tumbled jasper (likely brecciated jasper)

Microcrystalline quartz/chalcedony, SiO₂, colored by iron oxides

Petrified wood

Silicified fossil wood, commonly preserved as microcrystalline quartz (SiO₂)

Unidentified polished multicolored stone, possibly granite or mixed-mineral rock

Indeterminate from the photograph; no diagnostic mineral texture or composition is clear

Likely milky quartz pebble

Quartz (silicon dioxide, SiO₂)

Rounded quartz-rich pebble

Likely vein quartz or quartzite; exact identification is uncertain from the image

Tumbled banded agate

Chalcedony, a microcrystalline variety of quartz (SiO₂)

Polished banded agate

Microcrystalline quartz (SiO₂), chiefly chalcedony

Iron-stained quartz pebble

Quartz (SiO₂), with iron-oxide staining and possible minor host-rock inclusions

Tumbled brown agate

Microcrystalline quartz (chalcedony), SiO₂; likely brown banded agate

Orange chalcedony (likely carnelian)

Chalcedony, microcrystalline quartz (SiO₂); orange-red variety is called carnelian

Tumbled agate (possibly carnelian)

Microcrystalline quartz, SiO₂; likely chalcedony

Polished amber

Amber (fossilized plant resin; commonly succinite)