Metamorphic Or Igneous (Context Dependent)

Fluorite (left), Sodalite (middle), Dumortierite/Tumbled Quartzite (right)

Calcium Fluoride (CaF2), Sodium Aluminum Silicate Chloride (Na8(Al6Si6O24)Cl2), Aluminum Borosilicate (Al7(BO3)(SiO4)3O3)

Clear Quartz

Silicon Dioxide (SiO2)

Ruby

Corundum (Al2O3 with Chromium impurities)

Clear Quartz Crystal

Silicon Dioxide (SiO2)

Garnet (Almandine/Pyrope variety)

Silicate mineral group; typically Fe3Al2(SiO4)3 (Almandine) or Mg3Al2(SiO4)3 (Pyrope)

Quartz

Silicon dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Ruby

Corundum (Aluminum Oxide with Chromium), Al2O3:Cr

Quartz Pebble (with potential iron inclusions)

Silicon Dioxide (SiO2)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Moonstone (specifically Cat's Eye or Gray Moonstone)

Orthoclase (Potassium Aluminum Silicate) with the formula (K,Na)AlSi3O8

Labradorite

Plagioclase Feldspar ((Ca, Na)(Al, Si)4O8)

Black Tourmaline (Schorl)

Sodium Iron Aluminum Borosilicate (NaFe2+3Al6(Si6O18)(BO3)3(OH)3OH)

Clear Quartz

Silicon Dioxide (SiO2)

Citrine

Silicon Dioxide (SiO2) with iron impurities

Moonstone

Orthoclase (KAlSi3O8), specifically the variety showing adularescence

Moonstone

Orthoclase (Potassium Feldspar) - (K,Na)AlSi3O8

Quartz (Smoky Quartz variant)

Silicon Dioxide (SiO2)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Smoky Quartz

Silicon Dioxide (SiO2)

Milky Quartz with Iron Staining

Quartz (Silicon Dioxide, SiO2)

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Black Tourmaline

Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)

Clear Quartz

Silicon Dioxide (SiO2)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Moonstone (Feldspar)

Orthoclase feldspar, (K,Na)AlSi3O8

Quartz (Milky/Smoky variety)

Silicon Dioxide (SiO2)

Moonstone (Feldspar variety)

Orthoclase Feldspar (KAlSi3O8)

Yellow Quartz Pebble

SiO2 (Silicon Dioxide) with Iron Impurities

Quartz (Vein Quartz)

Silicon Dioxide (SiO2)

Garnet (specifically Almandine or Pyrope)

Almandine (Fe3Al2Si3O12) or Pyrope (Mg3Al2Si3O12)

Chlorite Included Quartz

Silicon Dioxide (SiO2) with Chlorite (Mg,Fe,Li)6AlSi3O10(OH)8

White Quartz Pebble

Silicon Dioxide (SiO2)

Smoky Quartz

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)