Industrial Byproduct (Anthropogenic Material)

Polished brecciated jasper (likely)

Brecciated jasper, an opaque microcrystalline quartz (SiO₂) with contrasting silica-rich fragments and matrix

Diamond (or Diamond Simulant)

Carbon (C) or Zirconium dioxide (ZrO2) for CZ

Small metallic meteorite fragment (probable stony-iron or iron meteorite)

Unclassified meteoritic material; exact classification requires chemical and petrographic testing

Fossil bivalve shell

Likely an extinct or modern-like ribbed cockle/scallop; exact genus requires locality and diagnostic hinge features

Schist

Mica Schist

Gold-bearing quartz or ironstone fragment

Quartz (SiO₂) with possible native gold and iron oxides

Man-made Metal Pin (Non-geological)

Antimony-Lead Alloy or Zinc/Brass Base with Electroplating

Diamond (or Cubic Zirconia simulant)

Carbon (C) or Zirconium Dioxide (ZrO2)

Small dark pebble, possibly basalt or slag

Likely fine-grained mafic rock; exact identification requires examination

Diabase

Diabase (also known as Dolerite)

Glass

Amorphous Silicon Dioxide (SiO2)

Paper (Cellulose)

Cellulose (C6H10O5)n

Polished black stone, likely basalt or fine-grained mafic rock

Basalt (probable; identification uncertain from photograph)

Man-made Carved Stone (Scream Mask/Skull motif)

Carved Soapstone or Serpentine-rich rock

Carborundum

Silicon Carbide (SiC)

Small rounded pebble

Indeterminate lithic grain; likely weathered sandstone, iron-stained quartz-rich rock, or a concretion

Quartzite

Quartzite (primarily SiO2)

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Laterite (Red Clay)

Laterite (Fe2O3 · nH2O and Al2O3 · nH2O)

Quartzite

Quartzite (primarily SiO2)

Basalt (Weathered)

Extrusive Igneous Rock (Mafic composition)

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Tumbled yellow quartz (likely citrine or iron-stained quartz)

Quartz, SiO₂; yellow color from trace iron or irradiation/heat-related coloration

Diamond

C (Carbon)

Tumbled jasper (likely)

Microcrystalline quartz, SiO₂; likely jasper, a variety of chalcedony

Mudstone

Lutylite (group of fine-grained sedimentary rocks)

Orbicular jasper (often sold as leopard-skin jasper)

Silicified volcanic tuff/rhyolite; chiefly microcrystalline quartz and chalcedony (SiO₂), with iron oxides and altered volcanic minerals

Dark metallic-looking mineral specimen, possibly magnetite

Magnetite (Fe₃O₄), tentative identification

Iron-rich laterite or limonite/goethite concretion

Hydrated iron oxides, chiefly goethite (α-FeO(OH)) and limonite (FeO(OH)·nH₂O)

Blue glass-like bead or gemstone keychain ornament

Indeterminate; likely cobalt-blue glass or synthetic blue spinel, not identifiable as a natural mineral from the image

Weathered volcanic rock fragment

Indeterminate fine-grained mafic-to-intermediate igneous rock; possibly andesite or basalt

Natural turquoise-bearing rock

Turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O, likely in a limonite or host-rock matrix

Weathered quartz-rich rock, possibly quartzite or chert

Quartz (SiO₂), likely in a quartzite matrix; exact identification is uncertain from the image

River Siltstone / Mudstone Pebble

Siltstone (composed of mixed silicate and carbonate minerals)

Carborundum (Silicon Carbide)

Silicon Carbide (SiC)

Agate

Silicon Dioxide (Chalcedony), SiO2

Granodiorite

Granodiorite

Likely metallic meteorite fragment

Undetermined iron or stony-iron meteorite; mineralogy requires testing

Sea Shell Fragment (Calcium Carbonate)

Aragonite / Calcite (CaCO3)

Bauxite

Aluminum ore (mixture of gibbsite Al(OH)3, boehmite γ-AlO(OH), and diaspore α-AlO(OH))

Polished/tumbled unakite (probable)

Unakite; epidote + pink potassium feldspar + quartz

Diamond (or Cubic Zirconia / Gemstone Ring)

C (Carbon) for natural Diamond