Industrial Byproduct (Anthropogenic Material)

Unidentified small rounded mineral/rock fragment

Indeterminate from image; possibly quartz or chalcedony with iron-oxide staining

Obsidian (likely black volcanic glass)

Obsidian; predominantly rhyolitic glass, mainly SiO₂

Likely small iron-rich concretion or weathered mineral fragment

Indeterminate; possibly limonite/goethite-bearing material with quartz or feldspar

Chert (Flint)

Chert (SiO2)

Small blue-green mineral or stone bead

Unidentified opaque blue-green mineral; the image is insufficient for reliable species identification

Diamond

Carbon (C)

Tumbled smoky quartz (probable)

Quartz, silicon dioxide (SiO₂), likely smoky variety

Diamond

Carbon (C)

Quartz vein in Host Rock

Crystalline Silicon Dioxide (SiO2) in Lithic Matrix

Small tumbled dark stone, possibly basalt or slag

Likely fine-grained basalt; exact identification is uncertain from the photograph

Dark river pebble, likely basalt or fine-grained volcanic rock

Basalt (probable); mostly plagioclase and pyroxene, with possible magnetite

Possible fossilized shell or fossil fragment

Indeterminate; possibly a small brachiopod or gastropod fossil in mineralized matrix

Chert (Chert Nodule)

Microcrystalline quartz (SiO2)

Blue slag glass / industrial glass fragment

Artificial silicate glass, composition variable; likely copper- or cobalt-colored furnace slag

Tumbled blue stone, likely sodalite

Sodalite (Na₈Al₆Si₆O₂₄Cl₂), possibly blue calcite or dyed quartz

Tumbled dark-blue stone, likely sodalite

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂ (tentative)

Tumbled blue stone, likely sodalite

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂; identification uncertain from image alone

Fossil bivalve shell

Fossilized mollusk (Bivalvia), likely oyster or related species; exact genus requires locality and preparation

Olivine (Peridot)

Magnesium Iron Silicate (Mg,Fe)2SiO4

Diamond (faceted)

Carbon (C)

Quartz-rich chalcedony (likely agate or jasper)

Microcrystalline quartz, SiO₂; possibly a quartzite or silicified rock

Gray chalcedony (common agate/jasper fragment)

Microcrystalline quartz, SiO₂; likely chalcedony with weathered host-rock rind

Iron-rich sandstone or ferruginous laterite

Ferruginous sandstone/laterite, chiefly quartz (SiO₂) cemented or stained by iron oxides (hematite Fe₂O₃, goethite FeO(OH))

Polished ocean jasper (orbicular jasper), possibly brecciated jasper

Microcrystalline quartz/chalcedony (SiO₂) with iron-oxide pigments and minor volcanic inclusions

Polished orbicular jasper (likely kambaba or ocean jasper)

Silicified microcrystalline quartz/chalcedony with iron-rich inclusions; mainly SiO₂

Polished pink tourmaline in quartz (likely tourmalinated quartz)

Quartz (SiO₂) with pink lithium-rich tourmaline, commonly elbaite

Cubic Zirconia (Simulated Diamond)

Zirconium dioxide (ZrO2)

Tumbled green aventurine

Quartz (SiO₂) with green mica or other inclusions

Gray Limestone

Calcium Carbonate (CaCO3)

Botryoidal chalcedony (likely moss or plume agate)

Microcrystalline quartz, SiO₂; chalcedony with possible iron/manganese inclusions

Diamond

Carbon (C)

Jasper

Silicon Dioxide (SiO2)

Rutilated quartz bead bracelet

Quartz, silicon dioxide (SiO₂), with rutile inclusions (TiO₂)

Likely iron meteorite

Iron meteorite, predominantly kamacite and taenite (Fe–Ni alloys)

Tiger iron (polished)

Banded iron formation composed mainly of hematite, magnetite, and quartz/jasper

Specular hematite (iron ore)

Hematite, Fe₂O₃; likely specularite, possibly mixed with magnetite/goethite

Vesicular basalt (scoria)

Basaltic scoria; chiefly plagioclase, clinopyroxene, olivine, and volcanic glass

Tumbled brown pebble

Indeterminate; possibly weathered basalt or iron-stained quartzite

Slate

Slate (Low-grade metamorphism of shale/mudstone)

Granodiorite Pebble

Granodiorite

Basalt

Basalt (Mafic Extrusive Igneous Rock)

Basalt

Basalt (Mafic volcanic rock)