Anthropogenic (Man Made Material Processed By Nature)

Limestone

Calcium Carbonate (CaCO3)

Granite

Phaneritic plutonic rock (SiO2 rich)

Chert breccia

Sedimentary Breccia (Microcrystalline Quartz)

Yellow tumbled/rough chalcedony, possibly citrine or dyed agate

Chalcedony (microcrystalline SiO₂), with yellow coloration likely from iron oxides; exact identification is uncertain from the photograph

Red Sandstone

Sedimentary Clastic Rock (Quartz Arenite)

Amethyst crystal cluster

Amethyst, purple quartz (SiO₂) colored mainly by iron impurities and irradiation

Jasper

Silicon dioxide (SiO2) with iron impurities

Granite Cobble

Phaneritic Felsic Igneous Rock (Granite)

Sandstone (Quartzose)

Arenite (primarily SiO2)

Quartz-bearing granite or gneiss fragment

Granite/gneiss composed mainly of quartz (SiO₂), feldspar, and minor mica or ferromagnesian minerals

Sandstone

Sedimentary Rock (Quartz arenite)

Hematite bead bracelet

Hematite (Fe₂O₃), likely polished or magnetically enhanced beads

Turquoise

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

Sandstone

Arenite (primarily SiO2)

Granite

Phaneritic Igneous Rock (Granite)

Polished orbicular jasper

Jasper, a microcrystalline variety of quartz (SiO₂), colored by iron oxides and other accessory minerals

Muscovite mica

Muscovite, KAl₂(AlSi₃O₁₀)(OH)₂

Sandstone (Micaceous/Feldspathic variant)

Arenite (specifically subarkose or lithic arenite)

Granite

Phaneritic plutonic rock (Quartz, Feldspar, Mica)

Limonite (Iron Ore)

Hydrous Iron Oxide (goethite, lepidocrocite)

Sandstone (Ferruginous)

Arenite with Iron Oxide (Fe2O3) cement

Sandstone

Sedimentary Clastic Rock (Quartz Arenite)

White seed-bead gemstone strand, likely freshwater pearl or shell pearl

Pearl: nacreous calcium carbonate, chiefly aragonite (CaCO₃) in conchiolin; identification uncertain from image

Serpentinite (likely)

Serpentinite, dominated by serpentine-group minerals (antigorite, lizardite, or chrysotile)

Chert (Jasper/Flint variety)

Silicon dioxide (SiO2)

Sandstone (Calcareous or Ferruginous)

Clastic sedimentary rock (SiO2 with CaCO3 or Fe2O3 cement)

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

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

Limestone (Grey and White specimens)

Calcium Carbonate (CaCO3)

Magnetite (Lodestone)

Iron(II,III) oxide (Fe3O4)

Polished black obsidian pyramid/block

Obsidian — natural volcanic glass, chiefly rhyolitic silica (approximately 70–75% SiO₂)

Turquoise

Turquoise (Hydrated phosphate of copper and aluminium) - CuAl6(PO4)4(OH)8·4H2O

Blue Sapphire and Diamond (Set in Metal)

Corundum (Al2O3) and Diamond (C)

Possible tektite or volcanic glass specimen

Natural silica glass; composition commonly near SiO₂, but exact identification requires chemical testing

Chalcedony (Yellow Agate)

Cryptocrystalline Quartz (SiO2)

Shale

Fissile mudrock (composed of clay-sized particles and detrital grains)

Red Sandstone

Arenite (Ferruginous Sandstone)

Dyed Blue Agate

Chalcedony (Silicon Dioxide / SiO2)

Ironstone Concretion / Goethite-Hematite Nodule

Goethite/Hematite (α-FeO(OH) / Fe2O3)

Red Sandstone

Quartzose Sandstone (primarily quartz grains cemented by iron oxides)

Jasper Marble

Silicon Dioxide (SiO2) with Impurities

Red Jasper

Silicon Dioxide (SiO2) with Hematite impurities

Granite

Phaneritic plutonic igneous rock (mostly SiO2 and Al2O3)