Mineral (Biogenic)

Banded Sandstone (Quartzite-rich)

Clastic Sedimentary Rock (SiO2 with Iron Oxide impurities)

Red Sandstone

Arenite (Ferruginous Sandstone)

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Limonite and Goethite (Ironstone)

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

Ferruginous Quartz (Iron-stained Quartz)

Silicon Dioxide (SiO2) with Hematite/Limonite impurities

Quartz Pebble

Silicon Dioxide (SiO2)

Jasper with Manganese Dendrites

Silicon Dioxide (SiO2) with Oxide Mineral Inclusions

Limonite

Hydrous Iron Oxide (often Goethite FeO(OH), Lepidocrocite γ-FeO(OH), and other amorphous iron oxyhydroxides)

Yellow Ocher (Limonite)

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

Rutilated Prehnite

Prehnite - Ca2Al(AlSi3O10)(OH)2 with Epidote/Tourmaline inclusions

Brecciated Chert

Sedimentary Chert (SiO2) with Calc-Silicate mineralization

Jasper (var. Ocean or Polychrome Jasper)

Silicon Dioxide (SiO2) with iron and mineral inclusions

Geode (unopened)

SiO2 - Chert-shelled concretion (mostly Quartz)

Quartzite Pebble

Quartzite (primarily SiO2)

Corundum (Ruby Variety)

Corundum (Al2O3)

Blue Quartz (Aventurine)

Silicon Dioxide (SiO2) with fibrous inclusions (commonly Dumortierite)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Blue Apatite

Apatite (Ca5(PO4)3(F,Cl,OH))

Chert (Red Jasper variant)

Microcrystalline Quartz (SiO2)

Quartz Pebble

Crystalline Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Schist

Mica Schist

Granite

Phaneritic Igneous Rock (Granite)

Pink Granite (with Potassic Feldspar and Quartz)

Felsic Intrusive Igneous Rock (Granite)

Amygdaloidal Basalt with Epidote

Vesicular Basalt with secondary Epidote/Quartz mineral infill

Granite

Phaneritic Igneous Rock (primarily Quartz, Feldspar, and Mica)

Milky Quartz

Silicon Dioxide (SiO2)

Quartzite River Rock with Dendrites

Metamorphosed Quartz-rich Sandstone with Manganese Oxide (MnO2) inclusions

Honeycomb Calcite

Calcite (Calcium Carbonate, CaCO3)

Dark-colored Igneous Rock (likely Basalt or Diabase)

Basalt (extrusive igneous) or Diabase (intrusive igneous)

Black Sapphire

Corundum (Al2O3 with iron and titanium impurities)

Milky Quartz

Silicon Dioxide (SiO2)

Kimberlite with Diamond

Kimberlite (Diamond formula: C)

Diorite (Polished River Pebble)

Diorite (Intermediate intrusive igneous rock)

Gneiss

Gneiss (Metamorphic rock composed primarily of quartz, feldspar, and mica)

Mica Schist with Quartz

Mica-Quartz Schist (Muscovite subclass)

Diorite

Diorite (plutonic igneous rock)

Pink Granite

Phaneritic Felsic Intrusive Igneous Rock

Shale

Fissile Mudrock (Clay-rich Sedimentary Rock)

Rhodochrosite

Manganese Carbonate (MnCO3)

Blue Apatite

Fluorapatite (Ca5(PO4)3F)