http://en.wiktionary.org/wiki/auriferous
http://www.thefreedictionary.com/argentiferous
http://www.syvum.com/cgi/online/serve.cgi/squizzes/chem/periodic1b.html
http://en.wikipedia.org/wiki/Argentum
http://en.wikipedia.org/wiki/Gold
http://en.wikipedia.org/wiki/Quartz#Milky_quartz
http://en.wikipedia.org/wiki/Quartz#Rose_quartz
http://en.wikipedia.org/wiki/Quartz
http://en.wikipedia.org/wiki/Gold_coins#Fineness_of_gold_coins
http://en.wikipedia.org/wiki/Metal_as_money
http://www.ukcoinpics.co.uk/metal.html#Elec
http://en.wikipedia.org/wiki/Gold_coins#Counterfeits
http://en.wikipedia.org/wiki/History_of_coins
http://en.wikipedia.org/wiki/Gold_coins
http://en.wikipedia.org/wiki/Coin
http://en.wikipedia.org/wiki/Coinage_metals
http://www.ukcoinpics.co.uk/metal.html
http://en.wikipedia.org/wiki/Aksumite_currency#Gold_coins
http://en.wikipedia.org/wiki/Ancient_Greek_coinage
Electrum Coins
http://www.limunltd.com/numismatica/articles/electrum-coins.html
http://www.innovx.com/products/DELTA
http://www.innovx.com/en/system/files/u1899/DELTA_Product_2_1_10_1.pdf
DELTA XRF Retail price: $3,200 - $3,300
http://www.alibaba.com/product-free/109297379/INNOV_X_Delta_Handled_XRF_Analyzers.html
http://en.wikipedia.org/wiki/Fort_Knox
http://en.wikipedia.org/wiki/Gold_bar
http://en.wikipedia.org/wiki/Gold_coins
http://en.wikipedia.org/wiki/Gold_standard
http://en.wikipedia.org/wiki/Gold_bullion#Bullion
http://en.wikipedia.org/wiki/Johnson_Matthey
http://www.matthey.com/about/preciousmetals.htm