Industrial Byproduct (Anthropogenic Material)

Polished fossil bone fragment

Fossilized bone, likely mammalian or reptilian; exact taxon cannot be determined from the image

Tumbled white quartz (likely milky quartz)

Quartz, silicon dioxide (SiO₂)

Rounded pale pebble, likely quartz-rich stone

Indeterminate; possibly quartzite, quartz-bearing granite, or calcite-rich limestone

Rounded gray pebble, likely quartz-rich stone

Indeterminate; possibly quartzite or a weathered granitic pebble

Dyed and polished agate pebble

Microcrystalline quartz (SiO₂), likely chalcedony/agate with blue dye

Banded quartz-rich pebble, possibly jasper or agate

Microcrystalline quartz (SiO₂), likely chalcedony/jasper with iron-oxide staining

Polished brown pebble

Indeterminate; possibly jasper, iron-rich quartzite, or a weathered ironstone pebble

Black Tourmaline (Schorl)

Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)

Basalt River Stone

Basalt (Aphanitic Mafic Igneous Rock)

Ferruginous Quartz (Iron-stained Quartz)

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Serpentine / Serpentinite (with Weathering Crust)

Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4

Tumbled banded chert or jasper

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

Polished/tumbled brown jasper or brecciated jasper

Microcrystalline quartz (SiO₂), commonly including hematite, iron oxides, and assorted silicified fragments

Polished chalcedony (likely jasper or agate)

Microcrystalline quartz, SiO₂; chalcedony with iron-oxide inclusions

Small pale rock fragment

Indeterminate; possibly quartz, calcite, or a weathered feldspar-rich fragment

Polished brown jasper (likely brecciated or orbicular jasper)

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

Olivine (Peridotite)

(Mg,Fe)2SiO4 (Magnesium Iron Silicate)

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily SiO2)

Jasper

Silicon dioxide (SiO2)

Banded Iron Formation (BIF)

Banded Iron Formation (Magnetite-Hematite-Chert)

Graphite

Graphite (Native Carbon, C)

Greenish Metamorphic Rock (likely containing epidote or chlorite)

Metamorphic rock, possibly epidosite or greenstone

Mica Schist

Mica Schist (primarily Muscovite and Biotite KAl2(AlSi3O10)(OH)2)

Quartzite

Quartzite (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Green aventurine (likely)

Quartz variety; silicon dioxide (SiO₂), commonly colored by fuchsite mica or other inclusions

Tumbled tiger’s eye

Tiger’s eye (chatoyant quartz), SiO₂ with fibrous crocidolite pseudomorphs

Fossilized bivalve shell

Bivalvia indeterminate; likely a fossil cockle or clam shell, aragonite/calcite replaced or preserved

Diamond (in Jewelry Setting)

Carbon (C) - Isometric-Hexoctahedral

Polished malachite–agate breccia (likely)

Microcrystalline quartz/chalcedony (SiO₂) with iron-oxide staining; exact identification requires testing

Likely quartz-rich pebble or weathered limestone fragment

Indeterminate; possibly microcrystalline quartz (SiO₂) or calcite-rich limestone (CaCO₃)

Pale green tumbled mineral, likely prehnite

Prehnite — Ca₂Al(AlSi₃O₁₀)(OH)₂; identification is provisional from the photograph

Smoky quartz (probable)

Quartz, silicon dioxide (SiO₂), brown smoky variety

Weathered fossil shell fragment

Indeterminate bioclastic carbonate, likely molluscan shell (calcium carbonate, commonly aragonite or calcite)

Rounded brown river pebble

Likely weathered sandstone or iron-stained quartz-rich rock; exact identification requires testing

Tumbled turquoise

Turquoise — hydrated copper aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O

Tumbled quartzite or quartz-rich beach stone

Quartzite; predominantly microcrystalline quartz (SiO₂)

Weathered iron-rich river pebble

Likely basalt or mafic rock with limonite/goethite staining

Rounded gray pebble, likely basalt or andesite

Fine-grained mafic to intermediate volcanic rock; commonly plagioclase with pyroxene and/or olivine

Blue-gray botryoidal mineral specimen

Likely botryoidal chalcedony or hemimorphite; species cannot be confirmed from the image alone

Amethyst crystal

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

Vesuvianite (Idocrase)

Vesuvianite, Ca10(Mg,Fe)2Al4(SiO4)5(Si2O7)2(OH)4