Uncertain

Brown chert or jasper fragment

Microcrystalline quartz (SiO₂), likely iron-stained chert/jasper

Granite fragment

Granite; predominantly quartz (SiO₂), feldspar, and mica

Fossil tooth fragment

Likely fossilized shark tooth or marine vertebrate tooth; exact taxon cannot be determined from the image

Greenish translucent glassy mineral specimen, possibly fluorite or quartz

Likely fluorite (CaF₂) or green quartz (SiO₂); exact identification requires hardness and cleavage tests

Likely coarse-grained granite or gneiss

Granite: quartz + feldspar + mica; possibly banded gneiss if metamorphic texture is present

Likely quartz-rich rock or weathered granite fragment

Granite-like quartz–feldspar aggregate; exact identification requires testing

Blue-violet faceted gemstone, likely amethyst

Quartz (SiO₂), purple variety colored mainly by iron impurities and irradiation

Tumbled quartz-rich stone, possibly smoky quartz or chert

Uncertain; likely microcrystalline quartz, SiO₂

Weathered vesicular volcanic rock (likely pumice or altered basalt)

Vesicular basalt–pumice, compositionally uncertain

Small rounded pebble (likely quartz or quartz-rich stone)

Uncertain; possibly microcrystalline quartz (SiO₂)

Weathered sandstone fragment

Quartz-rich sandstone (compositionally uncertain)

Pebble with dark mineral inclusion

Likely granitic or gneissic quartz–feldspar pebble with a mafic inclusion; exact identification requires testing

Tumbled dark limestone or basalt with a pale mineral vein

Likely micritic limestone (calcite, CaCO₃), possibly basalt with a calcite/quartz vein

Pale green calcite

Calcite (CaCO₃)

Druzy amethyst (likely)

Quartz, SiO₂, with purple coloration from trace iron and irradiation

Polished amber (possibly imitation or treated amber)

Amber—fossilized tree resin; mostly polymerized terpenoid compounds (not a mineral)

Chrysoprase-like green chalcedony (tentative)

Microcrystalline quartz, SiO₂, likely nickel-colored chalcedony; associated brown iron oxides

Weathered brown rock fragment

Indeterminate; possibly ferruginous sandstone or weathered volcanic rock

Blue glassy gemstone-like specimen

Indeterminate; possibly dyed or treated turquoise, blue apatite, or man-made glass

Quartz-rich breccia or vein quartz

Quartz (silicon dioxide, SiO₂), likely with iron-oxide staining and other pale gangue minerals

Tumbled green jasper or serpentine

Jasper: microcrystalline quartz (SiO₂); possible serpentine: Mg₃Si₂O₅(OH)₄

Brown tumbled stone, likely jasper or iron-rich chert

Microcrystalline quartz (SiO₂), possibly iron-oxide-bearing jasper/chert

Fossiliferous limestone

Bioclastic limestone, predominantly calcite (CaCO₃)

Polished agate/geode slice

Chalcedony (microcrystalline quartz, SiO₂), likely agate with an altered druzy/quartz interior

Mica-rich pegmatite (likely muscovite-bearing)

Granitic pegmatite composed mainly of quartz, feldspar, and mica; mica is likely muscovite, KAl₂(AlSi₃O₁₀)(OH)₂

Milky quartz (possible pale green quartz)

Quartz, silicon dioxide (SiO₂)

Granite (likely weathered granite or granitic gneiss)

Granite; chiefly quartz (SiO₂), feldspar, and mica

Tumbled jasper, likely ocean jasper

Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide and other mineral inclusions

Tumbled, iron-stained quartz-rich pebble

Likely quartz/chalcedony with iron-oxide staining; exact rock type cannot be determined from the image

Blue kyanite

Kyanite (Al₂SiO₅)

Calcite crystal cluster

Calcite (CaCO₃)

Dark green cabochon gemstone ring

Unknown; possibly green onyx (cryptocrystalline quartz, SiO₂) or another green gem

Milky quartz (likely)

Quartz, silicon dioxide (SiO₂)

Tumbled dark green stone, likely serpentine or greenstone

Serpentinite (hydrated magnesium silicate minerals, chiefly antigorite/lizardite); possible chlorite-rich greenstone

Tumbled carnelian/chalcedony

Cryptocrystalline quartz, SiO₂ (iron-bearing chalcedony)

Fossilized tooth or tooth fragment

Indeterminate vertebrate tooth; possibly a fossil shark tooth (Carcharodon/Carcharocles)

Native gold nugget or flake

Native gold (Au), possibly with minor silver/electrum

Fossil coral fragment

Fossilized colonial coral, commonly *Hexagonaria* (often called Petoskey stone) or related scleractinian/tabulate coral

Tumbled serpentine (likely)

Serpentine-group minerals, chiefly antigorite/lizardite; approximate formula Mg₃Si₂O₅(OH)₄

Fossilized mammalian tooth fragment

Likely a fossil molar or premolar; exact taxon cannot be determined from the image

Smoky quartz ring

Quartz, SiO₂ (likely smoky quartz)

Likely quartz-rich pebble or pale granite fragment

Uncertain; possibly granite or quartz (SiO₂)