What do Henry David Thoreau and Australian opal miner Lenny Cram have in common? Find out here.

The second-most valuable gem in the world Burmese Jade: The Inscrutable Gem. By R.W. Hughes, O. Galibert, G. Bosshart, F. Ward, Thet Oo, M. Smith, Tay Thye Sun and George Harlow.

A journey to Russia's jade mines. By Richard Hughes, with Nickolai Kouznetsov.

By Richard W. Hughes. Join the author as he pays a visit to the ruby and sapphire deposits of the lost island of Madagascar.

By R.W. Hughes and Vincent Pardieu, with Guillaume Soubiraa and Dana Schorr. The insane gem posse hits the trail in search of the lost mines of Marco Polo, finding spinels, rubies, and something far more valuable.