Metamorphic (Pseudo Igneous)

Black Tourmaline (Schorl)

Schorl (Sodium Iron Aluminum Borosilicate Hydroxide), NaFe2+3Al6Si6O18(BO3)3(OH)3OH

Clear Quartz Crystal

Quartz (Silicon Dioxide, SiO2)

Rough Gemstone Grains (Mixed Sapphires and Quartz)

Corundum (Al2O3) and Quartz (SiO2)

Biotite Mica

Biotite (K(Mg,Fe)3AlSi3O10(OH,F)2)

Amethyst

Silicon Dioxide with Iron impurities (SiO2)

Quartz (specifically Milky/White Quartz)

Silicon Dioxide (SiO2)

Quartz

Quartz (Silicon Dioxide, SiO2)

Smoky Quartz

Smoky Quartz (SiO2)

Prasiolite

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

River Cobble (likely Basalt or Metagraywacke)

Non-specific water-worn lithic fragment

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz (Milky/Smoky Crystal fragment)

Silicon Dioxide (SiO2)

Pyrite

Iron Sulfide (FeS2)

Smoky Quartz

Silicon Dioxide (SiO2) with aluminum impurities

Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Pyrite

Iron Sulfide (FeS2)

Smoky Quartz

Smoky Quartz (Silicon Dioxide, SiO2)

Biotite / Black Mica

Biotite K(Mg,Fe)3AlSi3O10(F,OH)2

Quartz

Silicon Dioxide (SiO2)

Rough Blue Sapphire

Corundum (Al2O3)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Blue Sapphire

Corundum (Al2O3)

Milky Quartz

Silicon Dioxide (SiO2)

Yellow Sapphire

Corundum (Al2O3)

Clear Quartz

Crystalline Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Quartz / Calcite Vein Rock

Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3)

Quartz Pebble (with probable Iron staining)

Silicon Dioxide (SiO2)

Quartz (Milky/Rose variety)

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Crystal Cluster

Silicon Dioxide (SiO2)

Blue Sapphire

Corundum (Al2O3)

Quartz (Water-worn Pebble)

Silicon Dioxide (SiO2)

Hematite

Iron(III) oxide (Fe2O3)

Milky Quartz with Mica

Silicon Dioxide (SiO2) with Muscovite Mica [KAl2(AlSi3O10)(OH)2]

Sunstone with Black Tourmaline (Arfvedsonite)

Feldspar (Na,Ca)(Al,Si)4O8 with Schorl Na(Fe3+)3Al6(Si6O18)(BO3)3(OH)3(OH)

Milky Quartz

Silicon Dioxide (SiO2)

Amazonite

K(AlSi3O8) - Lead-bearing Microcline (Tectosilicate)

Star Sapphire

Corundum (Al2O3) with Rutile inclusions

Quartz (Tumbled/Water-worn)

Silicon Dioxide (SiO2)