Sedimentary (Formed From Silica Deposits)

Limonite with Trace Fossils

Hydrous Iron Oxide Mixture (FeO(OH)·nH2O)

Travertine

Terrestrial Sedimentary Rock (Calcium Carbonate, CaCO3)

Yellow Calcite (Banded Calcite)

Calcium Carbonate (CaCO3)

Honey Calcite

Calcium Carbonate (CaCO3)

Chalk

Calcium Carbonate (CaCO3)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Jasper (Red Jasper)

Jasper (Silicon Dioxide, SiO2)

Gneiss

Gneiss (High-grade Metamorphic Rock)

Jasper

Jasper (Silicate mineral, SiO2)

Red Sandstone

Arenite (primarily Quartz with Hematite cement)

Jasper (Red Jasper)

Silicon Dioxide (SiO₂)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Tiger's Eye

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

Coquina

Bioclastic Limestone (composed primarily of CaCO3)

Milky Quartz Pebble (Iron-stained)

Silicon Dioxide (SiO2)

Nephrite Jade

Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)

White Agate (Tumbled)

Silicon Dioxide (SiO2) - Cryptocrystalline Chalcedony

Chert (Cherty Flint/Jasper variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Limonite and Goethite

Limonite (hydrated iron(III) oxide-hydroxide) and Goethite (α-FeO(OH))

Orange Satin Spar (Satin Spar Selenite)

Satin Spar - Hydrous Calcium Sulfate (CaSO4·2H2O)

Limonite (Iron Ore)

Limonite (an FeO(OH)·nH2O mineraloid, not a true mineral due to variable composition)

Agate

Banded Chalcedony (SiO2)

Blue Chalcedony (likely dyed Agate)

Silicon Dioxide (SiO₂)

Chrysocolla in Cuprite (Sonoran Sunrise)

Cu2-xAlx(H2-xSi2O5)(OH)4·n(H2O) (Chrysocolla) and Cu2O (Cuprite)

Rose Quartz

Silicon Dioxide (SiO2) with inclusions of Dumortierite or similar minerals

Chalcedony (Common Opal/Chert variety)

Silicon Dioxide (SiO2)

Agate Geode

Silicon Dioxide (SiO2) - Chalcedony / Quartz Variety

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Jasper with Quartz inclusion

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Green Jasper

Jasper (Silicon Dioxide, SiO2)

Porphyritic Basalt (Peanut Obsidian/Star Galaxy-style)

Porphyritic Basalt (Silica-rich Volcanic Rock)

Carnelian (a variety of Chalcedony)

Silicon dioxide (SiO2) with iron oxide impurities

Quartz Vein Rock

Quartz (Silicon Dioxide, SiO2)

White Quartz (Milky Quartz)

Quartz (Silicon Dioxide, SiO2)

Quartz (specifically Clear Quartz with iron/hematite staining)

Silicon Dioxide (SiO2)

Amethyst (Druzy Quartz)

Amethyst (Silicon Dioxide - SiO2 with iron impurities)

Mixed collection of Quartz varieties, Chalcedony, and metamorphic pebbles

Mixed gemstones (primarily Silicon Dioxide - SiO2)

Chert (Flint Nodules)

Silicon Dioxide (SiO2)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Pearl

Calcium Carbonate (CaCO3) with Conchiolin

Pyrite with Calcite

Iron Disulfide (FeS2) with Calcium Carbonate (CaCO3)