Organic (Non Rock)

Quartzite Pebbler

Quartzite (primarily SiO2)

Blue Chalcedony

Cryptocrystalline Quartz (SiO2)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Hematite

Hematite (Iron(III) oxide, Fe2O3)

Ruby

Corundum (Al2O3 with Chromium traces)

Quartz Pebble

Silicon Dioxide (SiO2)

Chrysoprase

Chalcedony (cryptocrystalline silica containing nickel); Chemical Formula: SiO2 with Ni impurities

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Carnelian Agate

Chalcedony (SiO2 with iron oxide impurities)

Green Aventurine

Silicon Dioxide with Fuchsite inclusions (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily SiO2)

Banded Agate

Agate (Cryptocrystalline variety of Quartz, SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Blue Chalcedony

Silicon Dioxide (SiO2)

Carnelian

Carnelian (SiO2)

Opal

Hydrated Silica (SiO2·nH2O)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Native Copper within Host Rock

Native Copper (Cu)

Yellow Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Sandstone

Arenite

Yellow Jasper

Silicon Dioxide (SiO2) with iron inclusions

Limonite Concretion

Limonite (Hydrated Iron Oxide) FeO(OH)·nH2O

Sandstone (Ferruginous)

Arenite (complex silicate composition with iron oxides)

Sandstone (Ferruginous)

Arenite with Iron-Oxide Cement

River Pebbles (Tumbled Quartz and Basalt)

Silicon Dioxide (SiO2) for white quartz; Mafic Volcanic Rock for basalt

Sandstone

Clastic Sedimentary Rock (composed primarily of Quartz, SiO2)

Basalt

Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)

Quartz Geode

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Ferruginous Sandstone

Arenite with Iron-oxide cement

Limestone (specifically Fossiliferous Limestone)

Calcium Carbonate (CaCO3)

Unakite

Epidotized Granite

Quartzite River Stone

Quartzite (SiO2)

Ferruginous Sandstone

Arenite with Iron-Oxide Cement (SiO2 with Fe2O3/FeO(OH))

Limestone

Calcium carbonate (CaCO3)

Sandstone

Clastic sedimentary rock (primarily SiO2)

Sandstone (Quartz-rich)

Arenite (composed primarily of SiO2)

Quartzite Cobble

Quartzite (primarily SiO2)

Sandstone (Ferruginous)

Arenite (composed primarily of SiO2 with Fe2O3 staining)

Basalt

Mafic volcanic rock (various silicate minerals including Pyroxene and Plagioclase)

Carnelian (Orange Chalcedony)

Silicon dioxide (SiO2)