Quartzite pebble

Quartzite (primarily SiO2)

metamorphic

Nephrite Jade

Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)

metamorphic

Apache Tear (Obsidian)

Volcanic glass (SiO2 - Silicon Dioxide)

igneous

Chert (Polished Gemstone / River Stone)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

sedimentary

Amethyst (Chevron or Banded Amethyst)

Silicon Dioxide (SiO2) with Fe3+ impurities

mineral

Red Jasper

Silicon Dioxide (SiO2)

sedimentary

Amethyst (Quartz)

Silicon Dioxide (SiO2) with iron impurities

mineral

Serpentine (Serpentinite)

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

metamorphic

Nephrite Jade

Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)

metamorphic

Ruby Zoisite

Anyolite (Zoisite with Ruby and Pargasite)

metamorphic

Basalt Pebble

Extrusive Mafic Igneous Rock

igneous

Quartzite

Quartzite (SiO2)

metamorphic

Schist/Phyllite

Metamorphic Schist (Chlorite Schist variety)

metamorphic

Pyrite

Iron Sulfide (FeS2)

mineral

Citrine

SiO2 (Silicon Dioxide)

mineral

Unakite (often traded as Dragon Blood Jasper)

Epidotized Granite

Metamorphic (Altered Igneous rock)

Quartz / Quartzite

Silicon Dioxide (SiO2)

metamorphic

Quartzite

Quartzite (primarily SiO2)

metamorphic

Quartzite

Quartzite (primarily SiO2)

metamorphic

Chert (Flint nodule)

Silicon dioxide (SiO2)

sedimentary

Basalt

Mafic Igneous Rock (primarily Plagioclase and Pyroxene)

igneous

Ironstone Concretion / Limonite-stained Siltstone

Ironstone (primarily Limonite FeO(OH)·nH2O and Siltstone)

sedimentary

Travertine (Calcareous Tufa)

Calcium Carbonate (CaCO3)

sedimentary

Milky Quartz

Quartz / Silicon Dioxide (SiO2)

mineral

Basalt

Basalt (Mafic igneous rock)

igneous

Quartz Pebble

Silicon Dioxide (SiO2)

mineral

Quartzite Cobble

Quartzite (primarily SiO2)

metamorphic

Basalt

Basalt (Aphanitic Mafic Igneous Rock)

igneous

Quartz (River Pebble)

Silicon Dioxide (SiO2)

mineral

Sandstone (Ferruginous)

Arenite with Iron Oxide cement (SiO2 + Fe2O3)

sedimentary

Milky Quartz

Silicon Dioxide (SiO2)

mineral

Basalt (Porphyritic)

Basalt (Mafic Extrusive Igneous Rock)

igneous

Quartz Pebble

Silicon Dioxide (SiO2)

Mineral / Sedimentary occurrence

Granite

Granite

igneous

Granite

Granite (Mainly Quartz, Alkali Feldspar, and Plagioclase)

igneous

Quartz (Common Quartz Pebble)

Silicon Dioxide (SiO2)

mineral

Quartz / Quartzite

Silicon Dioxide (SiO2)

Mineral / Metamorphic

Sandstone (Quartzose)

Arenite (composed mainly of SiO2)

sedimentary

Blue Goldstone

Aventurine Glass

Man-made mineral simulant (Glass)

Quartz Crystal Cluster

Silicon Dioxide (SiO2)

mineral

Yellow Jasper

Jasper (Silicon Dioxide, SiO2)

sedimentary

Quartz Crystal Cluster

Quartz (Silicon Dioxide, SiO2)

mineral