Banded Agate (specifically Sardonyx or Carnelian Agate)
Silicon Dioxide (SiO2) - Chalcedony variety
mineral
Banded Agate
Cryptocrystalline Quartz (SiO2)
mineral
Sodalite
Sodalite (Na8Al6Si6O24Cl2)
mineral
Orange Calcite (Carved as a Horned Skull)
Calcium Carbonate (CaCO3)
mineral
Pink Thulite (in Pumice-like texture)
Pink Zoisite (Mn-bearing Zoisite), Ca2Al3(SiO4)3(OH)
metamorphic
White Jade / Jadeite
NaAlSi2O6 (Sodium Aluminum Silicate)
metamorphic
Quartz Geode
Silicon Dioxide (SiO2) in a concretionary structure
sedimentary
Yellow Calcite
Calcium Carbonate (CaCO3)
mineral
Garnet in Matrix (Eclogite)
Eclogite, featuring Almandine or Pyrope Garnet [X3Y2(SiO4)3]
metamorphic
Granite
Plutonic felsic igneous rock
igneous
Granite
Granite (Felsic Intrusive)
igneous
Quartzite Pebble (with Iron Inclusions)
Metamorphic Rock (Mainly SiO2)
metamorphic
Pink Granite
Phaneritic Felsic Igneous Rock (Rich in K-Feldspar)
igneous
Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Granite
Granite (Mainly Quartz, Feldspar, and Mica/Amphibole)
igneous
Diamond
Diamond (pure Carbon, C)
mineral
Granite
Phaneritic Felsic Igneous Rock (Granite)
igneous
Granite
Granite (Felsic Plutonic Rock)
igneous
Granite Cobble
Felsic Intrusive Igneous Rock
igneous
Quartzite
Quartzite (primarily SiO2)
metamorphic
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Asphalt / Road Aggregate
Bituminous Conglomerate (synthetic)
sedimentary
Quartzite Pebble
Quartzite (SiO2)
metamorphic
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Coquina or Fossiliferous Limestone
Fossiliferous Calcarenite (CaCO3)
sedimentary
Gneiss
Gneiss
metamorphic
Pink Granite
Granite (Phaneritic intrusive igneous rock dominated by Quartz and K-Feldspar)
igneous
Lapis Lazuli
Lapis Lazuli (aggregate of Lazurite, Calcite, and Pyrite)
metamorphic
Amethyst
Amethyst (Silicon Dioxide, SiO2 with Iron impurities)
mineral
Fossilized Shark Tooth (Otodus obliquus)
Otodus obliquus (composed primarily of Fluorapatite)
mineral
Blue Lepidolite
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)
mineral
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Howlite (Dyed Turquoise)
Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)
mineral
Hematite
Iron(III) oxide (Fe2O3)
mineral
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Green Calcite
Calcium Carbonate (CaCO3)
mineral
Blue Onyx (Dyed Agate)
Cryptocrystalline Quartz (SiO2) with artificial pigment
mineral
Moonstone
Orthoclase Feldspar ((K,Na)AlSi3O8)
mineral
Chalcedony (Blue/Grey Lace Agate)
Silicon Dioxide (SiO2)
mineral
Red Tiger's Eye
Pseudomorph of Macrocrystalline Quartz after Crocidolite (SiO2)
metamorphic