Smoky quartz, emerald-cut, 1522 carats, Brazil 

Spodumene (kunzite), lilac, oval step-cut, 260 carats, Brazil 

Topaz, step-cut, 221 carats, Minas Gerais, Brazil 

Topaz, fancy-cut, naturally colored, 454 carats, Brazil 

Topaz, fancy-cut, naturally colored, 454 carats, Brazil 

Spodumene (kunzite), octagonal step-cut, 69.8 carats, Mawi deposit, Nuristan, Afghanistan 

Spodumene (kunzite), octagonal step-cut, 69.8 carats, Mawi deposit, Nuristan, Afghanistan 

Diamond, approximately 25 carats, attached to kimberlite 

Beryl (Emerald), terminated by basal pinacoids, L 4 cm, attached to limestone, from Muzo, Colombia 

Topaz, L 10 cm, associated with Muscovite, Ural Mountains, Mursinka 

Quartz (Agate), slice, from Brazil 

Audubon Gallery showing Audubon's coat, 1985 

Quartz, variety Amethyst, oval-cut stone, 158 carats, Ural Mountains, Russia 

Tourmaline, green crystals on quartz, Brazil 

Quartz, variety Amethyst, geode slice, 12 cm diameter, Uruguay 

Topaz, Brazilian Princess, modified square cushion cut, 21,005 carats (9.5 pounds), mined near Teofilo Otoni, Minas Gerais, Brazil 

Quartz varieties including rock crystal, smoky quartz, citrine, amethyst, rose quartz, and green quartz, weights range from 13.16 to 489.85 carats; cut gems, oval, pear-shaped, and star-shaped, from v 

Topaz crystal, H 2.5 cm, in gray quartz and muscovite, Pakistan, near Gilgit 

Quartz (Amethyst), group of deep reddish purple amethyst crystals, from Thunder Bay, Ontario, Canada 

Quartz plate in polarized light