Organic Gemstone

Larimar

Pectolite (NaCa2Si3O8(OH))

Labradorite

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

Chert / Jasper

Silicon Dioxide (SiO2)

Green Calcite

Calcium Carbonate (CaCO3)

Amethyst Quartz (Chevron Amethyst)

Silicon Dioxide (SiO2) with iron impurities

Amethyst

Silicon dioxide (SiO2) with iron impurities

Citrine Quartz (likely heat-treated)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Kimberlite

Kimberlite (Group I or II)

Blue Apatite

Apatite-(CaF), Ca5(PO4)3F

Clear Quartz Sphere

Quartz (Silicon Dioxide, SiO2)

Tiger's Eye

SiO2 (Silicon Dioxide with inclusions of Goethite/Limonite)

Milky Quartz Pebble

Crystalline Silicon Dioxide (SiO2)

Feldspar (Orthoclase)

Potassium Feldspar (KAlSi3O8)

Milky Quartz

Silicon Dioxide (SiO2)

Jasper

Silicon dioxide / Chalcedony (SiO2)

Chalcedony (Agate Nodules)

Silicon Dioxide (SiO2)

Rainbow Moonstone

White Labradorite (formula: (Na,Ca)(Al,Si)4O8)

Clear Quartz (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

Rose Quartz

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

Black Sapphire (Basaltic Blue Sapphire)

Corundum (Al2O3)

Smoky Quartz

Silicon Dioxide (SiO2)

Red Jasper (Brecchiated Jasper)

Silicon Dioxide (SiO2) with Hematite impurities

Quartz (Milky/Yellowish variety)

Silicon Dioxide (SiO2)

Milky Quartz

Crystalline Silicon Dioxide (SiO2)

Carnelian (Carnelian Agate)

Carnelian (Silicon Dioxide - SiO2)

Jasper (Imperial Jasper style)

Silicon Dioxide (SiO2) with impurities

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

Pseudomorph of Quartz after Crocidolite (SiO2)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Aventurine (Green Quartz)

Quartz with Fuchsite inclusions (SiO2 with K(Al,Cr)2(AlSi3O10)(OH)2)

Smoky Quartz

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Botryoidal Hematite (Kidney Ore)

Iron(III) oxide (Fe2O3)

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Red Jasper (Chert)

Silicon Dioxide (SiO2)

Tiger's Eye

Pseudomorph of quartz after crocidolite (SiO2 with iron oxide inclusions)

Nuummite

Antophyllite-Gedrite (Orthorhombic amphibole)

Chrysocolla and Azurite in Matrix

Hydrated copper phyllosilicate (Chrysocolla - Cu2H2Si2O5(OH)4) and Copper carbonate (Azurite - Cu3(CO3)2(OH)2)

Obsidian

Volcanic glass (Mainly SiO2)

Pegmatite

Coarse-grained Igneous Rock (Granitic Pegmatite)

Black Obsidian

Volcanic Glass (SiO2 + impurities)