Mineral (Iron Ore)

Jasper

Jasper (Silicon Dioxide, SiO2)

Orange Quartz with Epidote

Silicon Dioxide (SiO2) with Calcium Aluminum Iron Silicate hydroxide (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH))

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Iron Oxide cement)

Quartzite with vugs/druzy quartz

Crystalline Silicon Dioxide (SiO2)

Milky Quartz (Water-worn Pebble)

Silicon Dioxide (SiO2)

Quartz Pebble (Chalcedony/Agate variety)

Silicon Dioxide (SiO2)

Quartz (River Pebble)

Quartz (Silicon Dioxide, SiO2)

Jasper

Silicon Dioxide (SiO2)

Sandstone

Arenite (primarily SiO2)

Red Sandstone (Old Red Sandstone Pebble)

Arenite with iron oxide (Fe2O3) cement

Peridot (Olivine)

Magnesium Iron Silicate (Mg, Fe)2SiO4

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Basalt with Plagioclase Phenocrysts

Porphyritic Basalt

Quartzite (Yellow/Iron-stained Quartz)

Quartzite (primarily SiO2 with iron oxide impurities)

Chert (specifically Flint)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Basalt

Mafic Igneous Rock (composed primarily of plagioclase, pyroxene, and olivine)

Basalt

Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)

Picasso Stone

Metamorphosed Calcium Carbonate (Limestone)

Chert Pebble (Jasper/Quartz variety)

Microcrystalline Quartz (SiO2)

Mahogany Obsidian

Volcanic Glass (with inclusions of Magnetite or Hematite)

Sandstone

Quartz Arenite (a common type of sandstone, given the appearance), Arkose, Greywacke (depending on mineralogy)

Chert (specifically Yellow/Tan Chert)

Silicon Dioxide (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Jasper (Iron-rich Chalcedony)

Jasper (Microcrystalline Silicon Dioxide, SiO2 plus iron oxide impurities)

Milky Quartz with Iron Oxide Staining

Quartz (Silicon Dioxide, SiO2)

Basalt with Iron Oxidation

Mafic Igneous Rock (primarily Plagioclase and Pyroxene)

Chert (often called Jasper in this color variety)

Microcrystalline Quartz (SiO2)

Basalt

Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)

Sandstone (Quartz-rich)

Sandstone (SiO2 dominated)

Carnelian

Chalcedony (cryptocrystalline quartz), SiO2

Sandstone (likely Quartzose Sandstone)

Clastic Sedimentary Rock (primarily SiO2)

Citrine (likely Heat-Treated Amethyst)

Silicon Dioxide (SiO2)

Diabase (Greenstone)

Diabase (also known as Dolerite)

Sandstone (specifically Flagstone)

Arenite (primarily composed of SiO2)

Oolitic Limestone

Oolite (Sedimentary rock composed of CaCO3)

Pyrite on Quartz (Fool's Gold in Quartz)

Iron Sulfide (FeS2) on Silicon Dioxide (SiO2)

Bauxite (Laterite Clay)

Bauxite (mixture of Hydrous Aluminum Oxides: Gibbsite Al(OH)3, Boehmite and Diaspore AlO(OH))

Sedimentary Breccia

Breccia (Clastic Sedimentary Rock)

Peridot

Olivine (Magnesium Iron Silicate), (Mg, Fe)2SiO4

Moqui Marble (Moqui Ball)

Ironstone Concretion (Goethite/Hematite cemented Sandstone)

Green Jasper

Silicon Dioxide (SiO2) with impurities

Sandstone Cobble with Liesegang Rings

Arenite with iron oxide precipitation (SiO2 matrix with Fe2O3 banding)