Anthropogenic (Man Made Material Processed By Nature)

Dark coarse-grained rock, likely basalt or gabbro

Basalt (fine-grained) or gabbro (coarse-grained), composed mainly of plagioclase feldspar and pyroxene

Picture Jasper

Silicon Dioxide (SiO2) with iron oxide and mineral impurities

Likely basalt with a pale mineral-filled vesicle

Vesicular basalt, probably containing calcite or zeolite (uncertain from image)

Granite

Phaneritic plutonic rock (Quartz, Feldspar, Mica)

Magnetite / Hematite (Iron Ore Pebble)

Fe3O4 (Magnetite) / Fe2O3 (Hematite)

Chert or Chalcedony

Microcrystalline Quartz (SiO2)

Red Jasper

Jasper (Silicon Dioxide: SiO2 with Iron oxide inclusions)

Coquina / Fossiliferous Limestone

Fossiliferous Limestone (Calcite, CaCO3)

Citrine Quartz

Silicon Dioxide (SiO2) with ferric iron impurities

Bornite (“peacock ore”), likely weathered copper sulfide

Bornite, Cu₅FeS₄; possibly chalcopyrite, CuFeS₂, with iridescent tarnish

Shale with Iron Oxide Staining

Fissile Mudstone (primarily clay minerals and quartz)

Sandstone (likely Quartzose Sandstone)

Arenite (composed primarily of SiO2)

Turquoise

Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]

Rounded quartz-rich beach pebble

Likely quartzite or quartz-rich sandstone; predominantly quartz (SiO₂)

Orbicular jasper (orbicular chert), likely ocean jasper

Silicified microcrystalline quartz (chalcedony), SiO₂, with iron-oxide and/or clay-rich orbicules

Granodiorite with Quartz Veining

Granodiorite (containing Plagioclase Feldspar, Quartz, and Biotite/Hornblende) with Quartz (SiO2) veins

Citrine

Silicon Dioxide (SiO2)

Limonite/goethite-rich ironstone (probable)

Limonite, chiefly hydrated iron oxides; commonly goethite, α-FeO(OH), with possible quartz or host-rock inclusions

Diamond (or Diamond Simulant)

C (Carbon) or synthetic equivalent

Diamond (in a cluster setting)

Crystallized Carbon (C)

Polished serpentine pendulum

Serpentine-group minerals, chiefly antigorite/lizardite; approximate formula Mg₃Si₂O₅(OH)₄

Purple Turquoise (Composite Mojave Turquoise)

CuAl6(PO4)4(OH)8·4H2O (Hydrated copper aluminum phosphate composite)

Jasper (specifically Picture Jasper or Landscape Jasper)

Silicon Dioxide (SiO2) - Opaque variety of Chalcedony/Quartz

Limestone

Calcium Carbonate (CaCO3)

Fossil Coral

Rugose Coral or Tabulate Coral (Phylum Cnidaria)

Chalcedony (Dyed Agate and Citrine-style Quartz)

Silicon Dioxide (SiO2)

White chalcedony or quartz-rich pebble

Microcrystalline quartz (SiO₂), possibly with minor calcite or feldspar

White Howlite

Howlite (Calcium borosilicate hydroxide, Ca2B5SiO9(OH)5)

Citrine

Quartz (SiO2) - variety Citrine

Pyrite

Iron Disulfide (FeS2)

Asphalt (Bituminous pavement fragment)

Artificial conglomerate / Bitumen-Aggregate mixture

Purple Lava Rock / Vesicular Basalt

Vesicular Basalt (Mafic Extrusive Igneous Rock)

Turquoise

CuAl6(PO4)4(OH)8·4H2O

Diamond (or Diamond Simulant)

Carbon (C)

Diamond in Kimberlite

Diamond (C in Kimberlite)

Ruby

Corundum (Aluminum Oxide with Chromium), Al2O3:Cr

Dyed Agate Slice

Silicon Dioxide (SiO2) - variety of Chalcedony

Citrine Quartz

Silicon Dioxide (SiO2) with iron impurities

Rhinestone

Artificial Glass/Crystal

Faceted Clear Gemstone (Likely Quartz or Cubic Zirconia)

Silicon Dioxide (SiO2) or Zirconium Dioxide (ZrO2)

Moss Agate

Chalcedony (SiO2) with inclusions of manganese or iron oxide

Likely polished black stone or obsidian

Obsidian (volcanic glass), chiefly SiO₂