Anthropogenic Specimen (Man Made)

Amethyst

Amethyst (Silicon Dioxide - SiO2 with iron impurities)

Ferruginous Quartz

Silicon Dioxide (SiO2) with iron oxide inclusions

Turquoise

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

Moss Agate

Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxide

Orange Calcite

Calcite (Calcium Carbonate, CaCO3)

Yellow Jasper

Jasper (Silicon Dioxide, SiO2)

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions of Iron Oxide)

Chert (Yellow Jasper/Agatized Chert)

Microcrystalline Quartz (SiO2)

Yellow Jasper

Silicon Dioxide (SiO2) with iron inclusions

Moss Agate

Silicon Dioxide with inclusions (SiO2)

Rose Quartz

Crystalline Silicon Dioxide with trace Titanium/Manganese/Iron (SiO2)

Chrysocolla on Quartz

Chrysocolla (Cu2−xAlx(H2−xSi2O5)(OH)4·nH2O) often associated with Quartz (SiO2)

Labradorite

Labradorite, (Ca, Na)(Al, Si)4O8

Banded Chert with Quartz Veining

Microcrystalline Quartz (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Red Jasper

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

Chalcedony (Common Opal variant)

Silicon dioxide (SiO2) with microcrystalline structure

Jasper

Jasper (Silicon Dioxide, SiO2 plus iron oxide impurities)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Black Tourmaline in Quartz

Schorl (NaFe3Al6(BO3)3Si6O18(OH)4) in Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Chevron Amethyst

Silicon Dioxide (SiO2) with trace Iron impurities

Petrified Wood

Silicified Wood (SiO2)

Rose Quartz

Quartz (Silicon Dioxide) - SiO2

Amazonite in Matrix

Potassium Feldspar (Microcline), KAlSi3O8

Basalt River Pebble

Basalt (Mafic volcanic rock)

Granite

Phaneritic Igneous Rock (Granite)

Quartz (with inclusions / Sandstone fragment)

Silicon Dioxide (SiO2)

Sandstone Geode (Unbroken)

Siliciclastic sedimentary rock (primarily Quartz)

Amber (Copal)

Organic gemstone, fossilized tree resin (often immature amber or copal)

Jasper

Jasper (Silicon Dioxide, SiO2)

Quartz (Smoky/Milky variant)

Silicon Dioxide (SiO2)

Basalt with Plagioclase Feldspar

Basalt (mafic extrusive igneous rock) with plagioclase feldspar phenocrysts

Ferruginous Quartz

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Quartzite Pebble

Quartzite (primarily SiO2)

Limestone (specifically a Crushed Aggregate fragment)

Calcium Carbonate (CaCO3)

Banded Calcite (often commercially called 'Mexican Onyx')

Calcium Carbonate (CaCO3)

Sandstone (Iron-stained)

Arenite (composed primarily of SiO2 with Fe2O3 staining)

Chert (Jasper/Chalcedony)

Microcrystalline Silica (SiO2)

Quartzite

Quartzite (primarily SiO2)

Blue Sapphire

Corundum (Al2O3 with trace amounts of iron and titanium)