Granite

Basalt

Basalt (Mafic volcanic rock)

Pyrite

Iron Sulfide (FeS2)

Pyrite

Iron Disulfide (FeS2)

Red Quartzite River Stone

Quartzite (SiO2)

Aventurine

Silicon Dioxide (SiO2 with inclusions of Fuchsite mica)

Amethyst

Amethyst (Silicon Dioxide - SiO2 with impurities of iron)

Chert (Jasper/Flint variety)

Microcrystalline quartz (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Basalt

Basalt (dominated by plagioclase feldspar and pyroxene)

Red Quartzite / Metasandstone River Pebble

Quartzite (primarily SiO2 with hematite inclusions)

N/A - Image is non-geological

Acrylonitrile Butadiene Styrene (ABS) or Polypropylene (PP)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Yellow Calcite

Calcium Carbonate (CaCO3)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Green Aventurine

Aventurine Quartz (SiO2 with Fuchsite inclusions)

Clear Quartz Cluster

Silicon Dioxide (SiO2)

Pearl

Biogenic CaCO3 (Aragonite and Calcite)

Sandstone

Arenite (SiO2 primarily)

Amethyst (as seen in jewelry)

Amethyst (Silicon Dioxide SiO2 + Fe4+)

Diamond (in jewelry)

Carbon (C)

Blue Apatite

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

Clear Quartz

Silicon Dioxide (SiO2)

Chrysoprase

Chalcedony (Silicon Dioxide, SiO2), flavored by Nickel

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Tiger's Eye (dark/grey variant)

Pseudomorph of Quartz after Crocidolite (SiO2)

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Olivine Peridotite

Peridotite (comprising Olivine (Mg,Fe)2SiO4 and Pyroxene)

Quartz Pebble

Silicon Dioxide (SiO2)

Amber

Succinite (Resin)

Sandstone

Arenite (SiO2 primarily)

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Spinel

Magnesium Aluminum Oxide (MgAl2O4)

Milky Quartz

Silicon Dioxide (SiO2)

Emerald In Matrix

Beryl (Be3Al2Si6O18) with trace Chromium/Vanadium

Chert (Yellow/Tan variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Basalt River Cobble

Basalt (Composition primarily Plagioclase Feldspar and Pyroxene)

Silver (Native or Alloyed)

Ag (Argentum)

Dream Amethyst (Chevron Amethyst)

Silicon Dioxide (SiO2) with Ferric Iron impurities

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

Rough Diamond

Diamond (Native Carbon, C)

Druzy Quartz

Silicon Dioxide (SiO2)