All rocks & minerals

Quartz crystal, likely iron-stained quartz

Quartz (SiO₂)

Likely banded calcite (possibly satin spar gypsum)

Calcite (CaCO₃); alternatively gypsum, CaSO₄·2H₂O

Quartz cluster

Quartz (SiO₂), likely a drusy quartz coating on matrix

Fossil shark tooth

Fossilized shark tooth; species indeterminate from the image

Polished ammonite fossil

Ammonite; extinct cephalopod, likely a Jurassic or Cretaceous form

Mixed rock and mineral collection

Assorted geological specimens; individual species cannot be reliably identified from the image

Assorted mineral and rock collection

Mixed specimens; individual species cannot be reliably identified from the image

Polished jasper (likely brecciated or picture jasper)

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

Polished agate nodule with druzy center

Banded chalcedony (microcrystalline SiO₂), with quartz crystals lining a cavity

Polished banded agate (possibly Botswana agate)

Banded chalcedony, microcrystalline SiO₂

Polished black stone, likely obsidian

Obsidian — natural volcanic glass, compositionally silica-rich (typically rhyolitic)

Reddish sandstone (probable)

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

Banded ironstone (likely jasper-rich ironstone)

Iron-oxide-rich silica rock, chiefly hematite/goethite with microcrystalline quartz (jasper)

Polished banded agate

Agate, a microcrystalline variety of quartz (SiO₂)

Scoria (vesicular volcanic rock)

Basaltic or andesitic scoria; chiefly plagioclase, pyroxene, and iron-rich volcanic glass

Faceted pale-yellow gemstone, possibly citrine

Unidentified transparent gemstone; citrine is quartz (SiO₂)

Tumbled rose quartz

Quartz (SiO₂), likely rose quartz

Tumbled olive-green stone, possibly serpentine or nephrite jade

Undetermined; likely serpentine (Mg₃Si₂O₅(OH)₄) or nephrite, a tremolite–actinolite amphibole aggregate

Tumbled green aventurine (likely)

Quartz, SiO₂, with green fuchsite or other mineral inclusions

Milky quartz cluster

Quartz (silicon dioxide, SiO₂)

Polished dark green stone, possibly bloodstone (heliotrope)

Chalcedony, microcrystalline quartz (SiO₂); identification is uncertain from the image

Polished orange chalcedony (likely carnelian)

Microcrystalline quartz, SiO₂; carnelian is orange-red chalcedony

Quartz geode

Quartz (SiO₂), likely a quartz-lined geode with a chalcedony rind

Blue tumbled stone, possibly sodalite

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂ (tentative identification)

Rose quartz

Quartz (SiO₂), pink variety

Rose quartz

Quartz, SiO₂ (pink variety)

Pale green tumbled stone, possibly fluorite

Uncertain from the photo; appearance is consistent with fluorite (CaF₂)

Pale green fluorite crystal

Fluorite (calcium fluoride, CaF₂)

Green-yellow mineral fragment, possibly fluorite

Fluorite (CaF₂), tentative identification

Polished peach moonstone

Moonstone, a feldspar variety; likely orthoclase (KAlSi₃O₈)

Polished pink calcite (likely a small cabochon or tumbled piece)

Calcite, CaCO₃

Gold-bearing rock, possibly native gold in quartz or ironstone matrix

Native gold (Au); matrix not identifiable from the image

Orange calcite

Calcite, calcium carbonate (CaCO₃)

Honey calcite (rough calcite)

Calcite, CaCO₃

Citrine (natural quartz crystal)

Quartz, SiO₂; the yellow-brown color may be natural citrine or heat-treated amethyst

Tumbled hematite (speculative identification)

Hematite, α-Fe₂O₃

Possibly citrine (yellow quartz)

Quartz, SiO₂; variety uncertain from the image

Tumbled honey-colored quartz, likely citrine

Quartz (SiO₂); the orange color may be natural citrine or heat-treated amethyst

Tumbled Dalmatian stone (Dalmatian jasper)

Trade name; commonly a leucocratic igneous rock with dark aegirine/arfvedsonite-group inclusions, often sold as “Dalmatian jasper”

Polished orange banded agate

Chalcedony, microcrystalline quartz (SiO₂)

Tumbled amethyst

Amethyst, purple variety of quartz (SiO₂)

Tumbled amethyst (likely)

Quartz, SiO₂; purple variety known as amethyst