Anthropogenic (Man Made Material Processed By Nature)

Placer Gold Nugget

Native Gold (Au)

Green Banded Agate

Agate (Variety of Chalcedony/Quartz), SiO2

Banded Iron Formation

Banded Iron Formation (BIF)

River Pebble (Greywacke or Basaltic)

Massive Greywacke or Basaltic Andesite

Fossilized Shell in Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Turquoise

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

Slate

Foliated Metamorphic Rock (primarily composed of quartz, illite, and chlorite)

Diamond (in a jewelry setting)

Cubic Carbon (C)

Granite

Granite (Phaneritic intrusive igneous rock) - Composition: SiO2, Al2O3, K2O, Na2O

Picture Jasper

Silicon Dioxide (SiO2) with iron oxide and clay inclusions

Basalt

Basalt (Mafic volcanic rock)

Cinnabar in Quartz

Silicon Dioxide (SiO2) with Mercury Sulfide (HgS) inclusions

Red Jasper (Polished)

Silicon Dioxide (SiO2) with Hematite inclusions

Basalt with Mineral Vein (Cobble)

Basalt (with likely Quartz/Calcite vein)

Red Jasper (Banded Jasper)

Jasper (Silicon Dioxide, SiO2)

Jasper with Dendritic Inclusions

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Limestone (specifically Crushed Limestone/Calcictic)

Calcium Carbonate (CaCO3)

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Pyrite in Matrix (Fool's Gold)

Iron Disulfide (FeS2)

River Stone (likely Basalt or Chert)

Silicon Dioxide (SiO2) for chert or Mafic Extrusive Rock for basalt

Blue Howlite (Dyed)

Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)

Pearl

Aragonite (CaCO3 with conchiolin)

Jasper

Silicon dioxide (SiO2)

Milky Quartz (with Iron Oxide staining)

Silicon Dioxide (SiO2)

Shale

Fissile mudrock (composed primarily of clay minerals and quartz)

Jasper (specifically Yellow or Picture Jasper)

Silicon Dioxide (SiO2) with iron oxide inclusions

Red Jasper

Silicon Dioxide (SiO2) with Hematite impurities

Rough Quartz (Alluvial Pebbles)

Silicon Dioxide (SiO2)

Yellow Quartz (Chalcedony)

Quartz / Chalcedony (Silicon Dioxide, SiO2)

Red Jasper

Silicon Dioxide (SiO2)

Jasper with Agate and Quartz Inclusions

Silicon Dioxide (SiO2) - Chalcedony / Quartz aggregate

Red Jasper

Silicon dioxide (SiO2) with iron oxide inclusions

Chalk (Sedimentary Pebble)

Calcium Carbonate (CaCO3) - Biogenic Limestone

Milky Quartz

Silicon Dioxide (SiO2)

Jasper with Hematite inclusions

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3)

Quartz (Milky or White Quartz)

Silicon Dioxide (SiO2)

Limestone (specifically Marl or Chalk)

Calcium Carbonate (CaCO3)

Red Coral (Precious Coral)

Corallium rubrum (Calcium Carbonate, CaCO3)

Tumbled Stones (various)

Mixed Silica-based Minerals (primarily Quartz and Chalcedony)

Jasper (Red Jasper with Quartz veins)

Jasper (Silicon Dioxide, SiO2)

Amethyst (Agate/Chalcedony variety)

Silicon Dioxide (SiO2) with iron impurities

Sandstone (Ferruginous)

Clastic Sedimentary Rock (SiO2 with FeO/Fe2O3)