Uncertain

Rounded granite cobble

Granite, a coarse-grained felsic intrusive igneous rock composed mainly of quartz, potassium feldspar, plagioclase, and minor mica or amphibole

Unidentifiable Rock Fragment

Clear quartz crystal sphere

Quartz (silicon dioxide, SiO₂)

Reddish-brown rounded pebble, likely iron-stained sandstone or chert

Probable quartz-rich sandstone (SiO₂), possibly ferruginous chert; exact identification requires testing

Quartz crystal fragment in weathered host rock

Quartz (SiO₂), possibly in a feldspathic or iron-stained matrix

Calcite crystal fragment

Calcite (calcium carbonate, CaCO₃)

Polished blue-green stone, likely serpentine or chrysocolla-bearing rock

Serpentine-group minerals, chiefly Mg₃Si₂O₅(OH)₄; exact identification requires testing

Polished agate/chalcedony fragment

Microcrystalline quartz (SiO₂), likely banded chalcedony or agate

Rounded quartz-rich beach pebble

Likely milky quartz or quartzite (SiO₂)

Quartz-rich rock, likely chert or chalcedony

Microcrystalline silica (SiO₂), possibly quartz/chalcedony

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 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)

Green glassy cabochon, likely dyed or synthetic material

Uncertain; possibly green obsidian, chrysoprase, or synthetic glass

Likely weathered granite or granitic gneiss

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

Tumbled amber-like chalcedony or resinous fossil material

Likely chalcedony (microcrystalline SiO₂), though the appearance could also indicate copal/amber

Mixed tumbled gemstone collection

Varied minerals, likely including amethyst, sodalite/lapis lazuli, quartzite or aventurine, jasper, and agate/chalcedony

Blue sodalite-bearing rock, likely sodalite in nepheline syenite

Sodalite (Na₈Al₆Si₆O₂₄Cl₂), possibly in nepheline syenite

Polished orbicular jasper (likely ocean jasper)

Silicified volcanic rock; chiefly microcrystalline quartz (SiO₂), with feldspar and iron-rich alteration minerals

Rough amber-like brown mineral specimen

Uncertain from photograph; possibly iron-stained quartz, common opal, or resinous amber

Weathered granite (likely biotite granite)

Granite; interlocking quartz, feldspar, and mica, commonly with biotite

Weathered granite or granitic pebble

Granite; chiefly quartz, alkali feldspar, plagioclase, and minor mica/amphibole

Tumbled feldspar-rich stone, likely granite or granitic pegmatite

Quartz–feldspar aggregate; likely alkali feldspar and plagioclase with minor quartz, possibly altered

Mixed rock and mineral collection

Mixed lithologies; likely quartz, feldspar, basalt, granite, chert, sandstone, and metamorphic rocks

Tumbled milky quartz (probable)

Quartz, silicon dioxide (SiO₂)

Coarse-grained granite or granitic gneiss

Granite; primarily quartz (SiO₂), feldspar, and mica, possibly metamorphosed to gneiss

Likely rose quartz-bearing pegmatite

Quartz (SiO₂), probably with feldspar and iron-oxide staining

Polished copper-bearing rock, likely cuprite-rich copper ore

Cuprite (Cu₂O) with native copper and iron-oxide matrix, probable

Uncertain rounded gray stone

Possibly granite, gneiss, or a glacially transported granitoid

Uncertain small metallic-looking mineral/rock fragment

Indeterminate; possibly galena-bearing rock or metallic slag

Quartz-rich vein rock, likely milky quartz in weathered host rock

Milky quartz (SiO₂), probably with weathered feldspar and iron-oxide staining

Likely weathered sandstone or iron-rich chert fragment

Indeterminate; probable quartz-rich sandstone (SiO₂) with iron-oxide cement, possibly chert

Iron-rich chert or jasper pebble

Microcrystalline quartz (SiO₂), colored by iron oxides

Quartz crystal

Quartz (silicon dioxide, SiO₂), possibly milky quartz

Weathered iron-rich rock, likely laterite or ironstone

Ferruginous laterite/ironstone, composed mainly of goethite (FeO(OH)), hematite (Fe₂O₃), and clay minerals

Likely weathered basalt or basaltic rock

Basalt; primarily plagioclase feldspar, pyroxene, and commonly olivine

Iron-stained quartz-rich rock, possibly goethite-bearing quartz

Quartz (SiO₂) with iron oxides/hydroxides, likely goethite or limonite

Fossiliferous limestone, possibly containing a brachiopod or bivalve fossil

Calcite-rich limestone (CaCO₃), with an apparent shell impression or shell fragment

Orange chromium diopside (likely tumbled)

Diopside, CaMgSi₂O₆; orange color may reflect iron-rich composition or surface treatment/inclusion

Uncertain polymict breccia or altered volcanic rock

Likely hydrothermally altered volcanic breccia; exact mineral identification requires testing

Blue calcite (likely)

Calcite, calcium carbonate (CaCO₃)