Quartz (Smoky or Clear variety with inclusions)
Silicon Dioxide (SiO2)
mineral
Jasper
Silicon dioxide (SiO2)
sedimentary
Jasper
Silicon dioxide (SiO2)
sedimentary
Sandstone (Quartzose Sandstone)
Arenite (SiO2 principal component)
sedimentary
Carnelian
Carnelian (Silicon Dioxide, SiO2)
mineral
Blue Chalcedony
Silicon Dioxide (SiO2)
mineral
Asphalt (Bituminous pavement fragment)
Artificial conglomerate / Bitumen-Aggregate mixture
sedimentary
Granite
Phaneritic intrusive igneous rock (consisting mainly of Quartz, Alkali Feldspar, and Plagioclase)
igneous
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Quartzite
Quartzite (primarily SiO2)
metamorphic
Quartzite
Quartzite (SiO2)
metamorphic
Quartz with Pyrite inclusions
Silicon Dioxide (SiO2) with Iron Sulfide (FeS2)
mineral
Sodalite
Sodalite (Na8Al6Si6O24Cl2)
mineral
Quartzite (River Cobble)
Quartzite (SiO2 silicon dioxide)
metamorphic
Sandstone
Arenite (primarily SiO2)
sedimentary
Graphite
Graphite (Carbon, C)
metamorphic
Peridotite (Pyroxenite/Serpentinized Dunite)
Ultramafic Rock (consisting primarily of Olivine and Pyroxene)
igneous
Mica Schist (Garnetiferous)
Garnet-Mica Schist
metamorphic
Phyllite
Phyllite (Foliated metamorphic rock)
metamorphic
Clear Quartz / Rock Crystal
Silicon Dioxide (SiO2)
mineral
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions
metamorphic
Chert (and/or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Anthracite Coal
Anthracite (Carbon-based sedimentary-metamorphic rock)
metamorphic
Fossilized Shark Tooth
Carcharodon carcharias (fossilized) / Hydroxyapatite permineralized with silica or iron
sedimentary
Amethyst Geode
Silicon Dioxide (SiO2) - Amethyst variety of Quartz
mineral
Basalt with Amygdules
Amygdaloidal Basalt
igneous
Amethyst
Silicon Dioxide with Iron impurities (SiO2)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Basalt
Extrusive mafic igneous rock
igneous
Basalt
Basalt (Aphanitic Mafic Volcanic Rock)
igneous
Basalt
Basalt
igneous
Basalt (River Stone)
Basalt
igneous
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Serpentinite
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
metamorphic
Gneiss
Gneiss
metamorphic
Milky Quartz with Iron Staining
Quartz (Silicon Dioxide, SiO2)
mineral
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone (likely with Quartz Veining)
Arenite (primarily SiO2)
sedimentary
Diorite (River Pebble)
Diorite
igneous
Chert (Jasper variety)
Silicon Dioxide (SiO2)
sedimentary
Jasper
Silicon Dioxide (SiO2) - Jasper (Microcrystalline Quartz)
sedimentary
Quartzite
Quartzite (primarily SiO2)
metamorphic