Industrial Byproduct (Anthropogenic Material)

Diamond (Faceted Gemstone)

Native Carbon (C)

Polished kambaba jasper

Orbicular stromatolitic jasper; microcrystalline quartz (SiO₂) with chlorite/amphibole-rich inclusions

Quartzite

Quartzite (composed primarily of SiO2)

Diamond (Cut Gemstone)

Carbon (C)

Diamond (or Diamond Simulant)

Carbon (C)

Clam shell (likely a bivalve shell)

Bivalvia; shell composed primarily of calcium carbonate (usually aragonite and/or calcite)

Possible basalt or iron-rich slag-like geological specimen

Basalt (tentative); predominantly plagioclase and pyroxene, possibly with magnetite/iron oxides

Opaline Glass (Opalite)

Synthetic Silicon Dioxide Glass

Orbicular jasper (likely ocean or leopard jasper)

Siliceous microcrystalline quartz aggregate; mainly SiO₂ with iron oxides and accessory feldspar/carbonates

Cubic Zirconia

Zirconium Dioxide (ZrO2)

Diamond

Diamond (C)

Smoky quartz (polished cabochon or crystal piece)

Quartz, SiO₂; smoky variety

Vesicular basalt (likely scoria)

Basaltic scoria; predominantly plagioclase, pyroxene, and olivine in a mafic volcanic glass/microcrystalline matrix

Chert Nodule (Flint)

Microcrystalline Quartz (SiO2)

Polished amber agate pendant/beads

Chalcedony (microcrystalline quartz), SiO₂, likely iron-stained yellow-orange agate

Polished tiger’s-eye

Quartz variety, SiO₂, with crocidolite-derived iron inclusions

Mixed rock fragments, likely iron-stained quartz-rich material

Indeterminate mixture; visible pale fragments may be quartz or feldspar, with iron-oxide staining (goethite/limonite)

Polished black stone, likely obsidian

Volcanic glass (primarily SiO₂), probably black obsidian

Polished orbicular jasper (likely ocean jasper)

Silica-rich chalcedony/quartz with iron-oxide and other mineral inclusions; exact variety cannot be confirmed from the photo

Polished orbicular jasper (likely ocean jasper)

Silica-rich microcrystalline quartz/chalcedony, SiO₂; precise variety uncertain from the photo

Polished black pebble, likely basalt

Basalt, a fine-grained mafic volcanic rock composed mainly of plagioclase feldspar and pyroxene, commonly with olivine

Possible iron meteorite

Fe–Ni iron meteorite, possibly an ordinary chondrite or weathered iron-rich specimen

Opalite (likely imitation opal glass)

Man-made opalescent glass; not a natural mineral (often sold as opalite)

Engineered Quartz Stone

Agglomerated Quartz (SiO2 + Polymer Resin)

Milky quartz

Quartz (silicon dioxide, SiO₂)

Asphalt (Bituminous Concrete)

Bituminous Concrete / Pavement

Rounded gray river pebble, likely basalt or andesite

Fine-grained mafic volcanic rock; commonly basalt (plagioclase, pyroxene, and possible olivine)

Quartzite

Quartzite (chiefly SiO2)

Yellow faceted gemstone, likely citrine or synthetic glass

Citrine (quartz, SiO₂) is the leading natural possibility; visual identification is uncertain from the photograph

White quartz geode nodule

Quartz (SiO₂), likely a quartz-lined geode or vug in a host rock

Likely amazonite-bearing feldspar specimen

Amazonite, a green variety of microcline feldspar (KAlSi₃O₈), with pale feldspar or quartz matrix

Likely polished copper-bearing mineral specimen (possibly chrysocolla with iron-oxide staining)

Chrysocolla, Cu₂H₂Si₂O₅(OH)₄·nH₂O; identification uncertain from image

Orange chalcedony (possibly carnelian)

Microcrystalline quartz, SiO₂; orange chalcedony is commonly called carnelian

Small brown pebble, possibly chert or iron-stained quartz

Undetermined; visual identification is inconclusive

Tumbled yellow jasper or weathered quartz-rich rock

Microcrystalline quartz (SiO₂), likely jasper with iron-oxide staining and dark inclusions

Polished brecciated jasper

Jasper, an opaque microcrystalline variety of quartz (SiO₂), with angular fragments cemented by silica or iron oxides

Garnet, likely almandine–spessartine

Garnet-group nesosilicate; commonly almandine Fe₃Al₂(SiO₄)₃ or spessartine Mn₃Al₂(SiO₄)₃

Possible rough agate/chalcedony nodule

Microcrystalline quartz (SiO₂), likely chalcedony or agate

Fossil shell fragment, likely bivalve or brachiopod

Indeterminate fossilized mollusk/brachiopod; commonly calcite (CaCO₃)

Rounded gray-brown pebble

Indeterminate; likely weathered quartz-rich sandstone or fine-grained volcanic rock

Raw green chalcedony (likely chrysoprase or prehnite)

Microcrystalline quartz, SiO₂; possible prehnite, Ca₂Al₂Si₃O₁₀(OH)₂

Fossil brachiopod in limestone

Brachiopoda; commonly a spiriferid or strophomenid brachiopod preserved in calcite-rich limestone