Industrial Byproduct (Anthropogenic Rock)

Silver Nugget

Native Silver (Ag)

Diamond

C

Chert / Jasper

Silicon Dioxide (SiO2)

Faceted Clear Gemstone (Likely Quartz or Cubic Zirconia)

Silicon Dioxide (SiO2) or Zirconium Dioxide (ZrO2)

Diamond (or Diamond Simulant)

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

Diamond (or Simulant)

Carbon (C) or Cubic Zirconia (ZrO2)

Quartz (Float/Abraded)

Quartz (SiO₂)

Synthetic Convention Badge (Plastic/PVC)

Polyvinyl Chloride (PVC) / Polycarbonate

Cupronickel Coin

Copper-Nickel Alloy (typically 75% Cu, 25% Ni)

Banded Iron Formation

Banded Iron Formation (BIF)

Silicon

Silicon (Si)

Biotite Mica

Biotite, K(Mg,Fe)3AlSi3O10(F,OH)2

Pebble (likely Quartz or Chert)

SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.

Green calcite (likely)

Calcite — calcium carbonate, CaCO₃

Epidote

Epidote Group (e.g., Clinozoisite, Epidote, Piemontite), Epidote formula: Ca2(Al,Fe)3(SiO4)3(OH)

Diamond (likely facet or crystal shard)

Diamond (C)

Tiger’s eye

Quartz variety, primarily silicon dioxide (SiO₂); fibrous quartz pseudomorph after crocidolite asbestos

Anthracite Coal

Anthracite

Red Garnet

Almandine Garnet (Fe3Al2(SiO4)3)

Dalmatian jasper

Orbicular rhyolite, commonly marketed as Dalmatian jasper; quartz–feldspar volcanic rock with dark aegirine/arfvedsonite-like inclusions

Banded Iron Formation (Jaspillite)

Banded Iron Formation (BIF)

Diamond

Diamond (C)

Coal (most likely Bituminous or Anthracite)

Bituminous Coal (Grade of Coal), Anthracite (Grade of Coal)

Blue-green copper mineral specimen, likely chrysocolla-bearing rock

Chrysocolla, hydrated copper phyllosilicate: approximately (Cu,Al)₂H₂Si₂O₅(OH)₄·nH₂O; possibly mixed with malachite or chrysocolla matrix

Kaolin (China Clay)

Kaolinite [Al2Si2O5(OH)4]

Agate

Chalcedony (SiO2)

Diamond and Sapphire

Carbon (Diamond, C) and Aluminum Oxide (Sapphire, Al2O3)

Ruby

Corundum (Al2O3 with Chromium trace)

Diamond (or Cubic Zirconia)

Carbon (C) / Cubic Zirconium Dioxide (ZrO2)

Rough Diamond

Diamond (pure Carbon, C)

Cubic Zirconia

Zirconium Dioxide (ZrO2)

Opalite

Man-made glass (traditionally simulated Opal)

Chalcedony (Agate/Jasper mix in host rock)

Chalcedony (cryptocrystalline Silicon Dioxide, SiO2)

Hematite or Goethite-rich Ironstone

Ironstone (Oxidized Iron Ore)

Rock Crystal Quartz

Quartz (SiO₂)

Quartz Pebble

Silicon Dioxide (SiO2)

Wishing Stone (Quartz-veined Metamorphic/Sedimentary Rock)

Quartz Vein in Greywacke/Slate (SiO2 in host rock)

Orthoclase Feldspar

Orthoclase (KAlSi3O8)

Quartzite

Quartzite

Sand Grain (Silica/Quartz Grain)

Silicon Dioxide (SiO2)

Rough Diamond

Diamond (Native Carbon, C)

Limonite (Ironstone Concretion)

Limonite (Hydrous ferric oxide mixture, FeO(OH)·nH2O)