Industrial Byproduct

Small iron-stained pebble

Likely iron-oxide-stained quartz-rich rock; exact identification is not possible from the image alone

Small pale stone fragment (undetermined)

Unidentified; the image lacks diagnostic detail for a reliable identification

Polished ocean jasper (orbicular chalcedony)

Silica-rich microcrystalline quartz, SiO₂; commonly sold as ocean jasper

Diamond (or Cubic Zirconia)

Cubic Carbon (C) or Zirconium Dioxide (ZrO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Diamond (or Cubic Zirconia)

Carbon (C) or Zirconium Dioxide (ZrO2)

Banded Serpentinite with Calcite Veins

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

Clear Quartz / Diamond (untested)

Silicon Dioxide (SiO2) or Carbon (C)

Diamond

Carbon (C)

Quartz Pebble

Silicon dioxide (SiO2)

Quartz Pebble

Silicon dioxide (SiO2)

Agate

Silicon dioxide (Chalcedony), SiO2

Native Copper

Copper (Cu)

Quartz Vein with Host Rock (Greywacke/Siltstone)

Silicon Dioxide (SiO2) within Clastic Sedimentary/Metamorphic Matrix

Faceted Diamond or Cubic Zirconia

Carbon (C) for Diamond; Zirconium dioxide (ZrO2) for CZ

Basalt (River Stone)

Basalt

Silver (Native Silver Mineral)

Ag (Native Silver), Alloyed 90% Ag / 10% Cu

Diamond (or Cubic Zirconia simulant)

Carbon (C) or Zirconium Dioxide (ZrO2)

Carborundum

Silicon Carbide (SiC)

Likely iron meteorite fragment

Iron–nickel meteorite, probably kamacite with taenite; identification is uncertain from the photo alone

Diamond stud earrings

Diamond, crystalline carbon (C)

Small dark pebble, possibly basalt or slag

Likely fine-grained mafic rock; exact identification requires examination

Schist

Mica Schist (formula variable based on mineral content, typically containing [K,Al,Fe,Mg,Si,O,H])

Kaolinite (China Clay)

Kaolinite (Al2Si2O5(OH)4)

Quartzite

Quartzite (composed primarily of SiO2)

Bauxite

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

Quartzite

Quartzite (principally SiO2)

Quartzite

Quartzite (primarily SiO2)

Limestone (Travertine/Tufa variant)

Calcium Carbonate (CaCO3)

Vesicular Basalt (or Scoria)

Extrusive mafic igneous rock

Pumice

Pumicite (Volcanic glass with vesicular texture)

Pumice

Pumiceous rhyolite

Fossiliferous Limestone

Calcite-rich Fossiliferous Limestone (CaCO3)

Limestone

Calcium Carbonate (CaCO3)

Pumice

Pumice (a vesicular volcanic glass)

Bituminous Coal

Organic Sedimentary Rock (Carbon-based)

River Stone (likely Siltstone or fine-grained Quartzite)

Sedimentary clastic rock containing SiO2 and iron oxides

Pumice

Pumice (a highly vesicular volcanic glass)

Pumice

Pumice (Vesicular Felsic Glass)

Vesicular Basalt

Aphanitic Mafic Volcanic Rock

Quartzite River Stone

Quartzite (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)