Synthetic Glass (Often Categorized As A Simulated Mineral)

Amethyst Lace Agate / Banded Amethyst

Silicon Dioxide (SiO2) with Fe3+ impurities

Garnet (Almandine)

Almandine (Fe3Al2(SiO4)3)

Quartzite Pebble

Meta-quartzite

Sandstone

Arenite (composed primarily of SiO2)

Scoria

Extrusive Basaltic Scoria

Tahitian Pearl

Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3

Quartz (River Pebble)

Quartz (Silicon Dioxide, SiO2)

Citrine

Silicon Dioxide (SiO2)

Pyrite

Iron Sulfide (FeS2)

Banded Agate (specifically Red Agate or Sardonyx variety)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Pyrite in Matrix (likely Quartz or Schist matrix)

Iron Sulfide (FeS2)

Howlite

Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)

Chert / Flint Nodules

Cryptocrystalline Quartz (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Rough Rose Quartz

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

Red Rhyolite Porphyry

Rhyolite (Porphyritic texture)

Sodalite

Sodalite - Na8(Al6Si6O24)Cl2

Pyrite

Iron Sulfide (FeS2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Quartzite with inclusions

Metamorphosed Quartz-rich Rock (SiO2)

Calcite

Calcite (Calcium Carbonate, CaCO3)

Emerald

Beryl (Be3Al2Si6O18) with trace amounts of Chromium and/or Vanadium

Sandstone

Clastic Sedimentary Rock (composed mostly of quartz and/or feldspar)

Sandstone

Arenite (Sedimentary rock comprising sand-sized grains)

Ferruginous Quartz

Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions

Jasper

Silicon Dioxide (SiO2)

Muscovite Mica

Muscovite - KAl2(AlSi3O10)(OH)2

Citrine (Iron-stained Quartz)

Silicon Dioxide (SiO2)

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Chalcedony (specifically Agate or Carnelian pebble)

Chalcedony (Microcrystalline Quartz, SiO2)

Yellow Quartz (Citrine or Iron-Stained Quartz)

Silicon Dioxide (SiO2)

Smoky Quartz (Tumbled)

Silicon Dioxide (SiO2)

Chert (and/or Flint)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Quartz (likely milky/rose quartz variety)

Quartz (SiO2 - Silicon Dioxide)

Pumice

Pumice (a highly vesicular, silicic volcanic rock)

Quartzite

Quartzite (primarily SiO2)

Yellow Quartzite

Quartzite (primarily SiO2)

Agate (Beads)

Silicon Dioxide (SiO2)

Sandstone (Ferruginous)

Arenite (Fe-bearing Clastic Sedimentary Rock)

Chert (Red Jasper variant)

Microcrystalline Quartz (SiO2)

Quartz

Quartz (SiO₂)