Metamorphic Rock (Variety Of Quartz)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Quartzite pebble

Metamorphic Quartzite (primarily SiO2)

Gneiss (Metamorphic Rock)

Gneiss

Quartzite

Metamorphosed Quartz Sandstone (SiO2)

Banded Chert

Microcrystalline Quartz (SiO2)

Milky Quartz (or Iron-Stained Quartz)

Quartz (Silicon Dioxide, SiO2)

Yellow Quartzite (River Pebble)

Quartzite (primarily SiO2 with iron oxide inclusions)

Schist

Mica Schist

River Quartz / Quartzite Pebbles

Quartzite (primarily Silicon Dioxide, SiO2)

Rough Garnet in Matrix

Almandine Garnet (Fe3Al2Si3O12)

Serpentinite

Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4

Quartzite (Ferruginous)

Quartzite (major component SiO2 with Fe2O3 impurities)

Amethyst (Druze)

Silicon Dioxide (SiO2) with iron impurities

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Jasper with Quartz Veining

Silicon Dioxide (SiO2) with iron oxide inclusions

Agate (Slab)

Agate (Cryptocrystalline variety of Quartz, SiO2)

Quartz (Clear Quartz/Rock Crystal)

Silicon Dioxide (SiO2)

Sandstone (Stream-rounded)

Arenite (SiO2 based)

Sandstone (likely Quartzose Sandstone)

Arenite (SiO2 predominantly)

Conglomerate

Clastic Sedimentary Rock (Conglomerate)

Quartz (Smoky/Grey variety)

Silicon Dioxide (SiO2)

Serpentine

Serpentine group, including Antigorite, Lizardite, and Chrysotile (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4

Red Jasper with Quartz Veining

Silicon Dioxide (SiO2) - Microcrystalline Quartz with Iron Oxide impurities (Hematite)

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Granitic Gneiss

Gneiss (High-grade regional metamorphic rock)

Conglomerate

Conglomerate rock

Quartzite Pebble

Quartzite (primarily SiO2)

Banded Onyx (Calcite Marble)

Calcite (CaCO3) - Trap-rock or Cave Onyx

Jasper (Red/Brown Variety)

Jasper (Silicon Dioxide, SiO2 plus Iron Oxide impurities)

Quartzite (Tumbled Pebble)

Metamorphosed Quartz Sandstone (SiO2)

Greenstone (Epidote/Chlorite-rich Metabasalt)

Greenschist / Epidosite (Ca2(Al,Fe)3(SiO4)3(OH))

Green Aventurine

Aventurine Quartz (SiO2 with inclusions of Fuchsite)

Banded Gneiss (with possible weathered sulfide or iron staining)

Gneiss, potentially with iron oxide/hydroxide staining (e.g., limonite) or weathered sulfides

Banded Gneiss

Gneiss (variable mineral composition)

Gneiss

Metamorphic rock of high-grade regional metamorphism

Serpentinite

Serpentinite (composed primarily of Serpentine group minerals: (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4)

Tiger's Eye (likely Hawk's Eye variant)

Pseudomorph of Quartz after Crocidolite (SiO2)

Quartz

Silicon Dioxide (SiO2)

Chert (Chalk-associated Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Quartzite Pebble

Quartzite (SiO2)