Mineral, Organic Gemstone

Emerald

Beryl (Be₃Al₂Si₆O₁₈), specifically the green variety colored by trace amounts of chromium or vanadium.

Ruby

Corundum (Al2O3) with Chromium traces

Red Jasper (Polished)

Silicon Dioxide (SiO2) with Hematite inclusions

Glauconitic Sandstone

Glauconitic Quartz-Wacke / Sandstone (Fe(II),Fe(III),Al,Mg)2-3(Si,Al)4O10(OH)2

Diamond in Gold Setting

Diamond (C - pure carbon)

Hematite

Iron(III) oxide (Fe2O3)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Moonstone

Orthoclase feldspar ((K,Na)AlSi3O8)

Quartz (Milky/Clear Variety)

Silicon Dioxide (SiO2)

Milky Quartz

Crystalline Silicon Dioxide (SiO2)

Yellow Aventurine

Quartz (Silicon Dioxide) with Mica inclusions (SiO2)

Turquoise in Matrix

Hydrated phosphate of copper and aluminium: CuAl6(PO4)4(OH)8·4H2O

Milky Quartz (Vein Quartz)

Silicon Dioxide (SiO2)

Lapis Lazuli

Complex mixture of minerals (lazurite, calcite, pyrite, and sodalite); (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2

Tiger's Eye

Silicon Dioxide (SiO2)

Quartz (Milky/Clear variety)

Silicon Dioxide (SiO2)

Quartz (specifically Clear Quartz with iron/hematite staining)

Silicon Dioxide (SiO2)

Labradorite

Labradorite (Plagioclase Feldspar Series) - (Ca, Na)(Al, Si)4O8

Amethyst

Amethyst (Silicon Dioxide - SiO2 with ferric impurities)

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Garnet

Garnet Group (Silicate Minerals), formula varies e.g., Almandine Fe3Al2(SiO4)3

Prehnite

Prehnite - Ca2Al(AlSi3O10)(OH)2

Milky Quartz

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Obsidian

Obsidian (Amorphous volcanic glass, predominantly SiO2)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)

Quartz (Milky/Clear)

Silicon Dioxide (SiO2)

Jasper

Silicon Dioxide (SiO2)

Epidote

Epidote (formula: Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))

Turquoise

Hydrated phosphate of copper and aluminium - CuAl6(PO4)4(OH)8·4H2O

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with iron inclusions)

Kyanite (Purple variety)

Kyanite (Al₂SiO₅)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Labradorite/Larvikite

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

Chrysoprase

Silicon dioxide with nickel impurities (SiO2 + Ni)

Chalcedony (Botryoidal Agate)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Quartz (Milky/Clear Quartz)

Silicon Dioxide (SiO2)