None

Limonite (with goethite)

Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)

Quartzite

Quartzite (SiO2)

Chert (specifically Flint or Common Chert)

Silicon Dioxide (SiO2)

Ametrine

Ametrine (SiO2 - Silicon Dioxide with varied iron impurities)

Fancy Jasper

Silicon Dioxide (SiO2) with impurities

Chert (Jasper variation)

Silicon Dioxide (SiO2)

Chert (Arrowhead/Projectile Point)

Microcrystalline quartz (SiO2)

Chert River Pebble

Microcrystalline Quartz (SiO2)

Chert (Flint) Nodule

Cryptocrystalline Quartz (SiO2)

Black Jasper (Black Onyx substitute)

Silicon Dioxide (SiO2) with carbonaceous impurities

Chert (Quartz Variety)

Microcrystalline Silicon Dioxide (SiO2)

Obsidian

Volcanic Glass (SiO2 - Silicon Dioxide with impurities)

Sandstone Concretion

Clastic sedimentary rock (primarily Quartz SiO2)

Black Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Fossiliferous Limestone

Bioclastic Limestone (CaCO3)

Schist (Oxidized)

Mica Schist with Iron Oxide staining

Quartz Geode / Druzy Quartz

Silicon Dioxide (SiO2)

Chalcedony (Agatized Coral / Rough Chalcedony Node)

Silicon Dioxide (SiO2)

Aqua Aura Quartz

Silicon Dioxide (SiO2) bonded with Gold (Au)

Clear Quartz

Silicon Dioxide (SiO2)

River Stone (Chert/Basalt mix)

Microcrystalline Quartz (Chert) / Basalt

Shungite

Shungite (Non-crystalline carbon, C)

Blue Agate (Dyed)

Silicon Dioxide (SiO2) - Variety of Chalcedony

Rose Quartz in Matrix

Silicon Dioxide (SiO2) with traces of Titanium, Iron, or Manganese

Leopard Skin Jasper

Orbicular Jasper (Silicon Dioxide, SiO2)

Quartz with Mica/Host Rock

Silicon Dioxide (SiO2) with Phyllosilicates

Obsidian

Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)

Banded Rhyolite (Wonderstone)

Rhyolite (High-silica volcanic rock)

Chert

Chert (Microcrystalline Quartz, SiO2)

Citrine Quartz

Silicon Dioxide (SiO2)

Obsidian

Volcanic Glass (70-75% SiO2)

Dinosaur Fossil (Tyrannosaurus rex skull replica/specimen)

Tyrannosaurus rex (fossilized in permineralized sedimentary matrix)

Garnet (Rough Almandine Crystal)

Almandine Garnet (Fe3Al2(SiO4)3)

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Banded Sandstone (Liesegang Rings)

Sedimentary sandstone with Iron oxide precipitates

Gold Nugget

Native Gold (Au)

Sandstone with Liesegang Rings

Clastic Sedimentary Rock with Iron Oxide Precipitates (SiO2 + Fe2O3)

Red Sandstone

Arenite (Ferruginous Sandstone)

Yellow Ochre / Limonite

Limonite (Hydrated Iron(III) Oxide-Hydroxide, FeO(OH)·nH2O)

Quartz Pebble

Silicon Dioxide (SiO2)

Rose Quartz

Silicon Dioxide (SiO2) with trace Titanium, Iron, or Manganese

Ruby (Faceted)

Corundum (Al2O3:Cr)