Imperial and US customary measurement systems the Troy units of weight—the troy ounce used to this day for weighting precious metals. Edward I (1272–1307) broke the link between a coin's value and its weight when he debased the English coinage by introducing a groat (four pence) which weighed of 89 grains rather than the expected 96 grains. The groat was further devalued in the 1350s when its weight was reduced to 72 grains. During Saxon times land was measured both in terms of its economic value and in terms of its size. The Domesday Book used the hide, an economic unit of measure. In other references
Wheaton Precious Metals Corporation 2017 Silver Wheaton reported attributable production totaling 6.5 million ounces of silver and 84,900 ounces of gold, equal to 12.5 million silver equivalent ounces. The Company reported net earnings for the quarter of $61 million or $0.14 per share. On May 10, 2017, Silver Wheaton says shareholders approved a company name change to Wheaton Precious Metals, effective immediately. Silver Wheaton was established in 2004. It was previously controlled by Goldcorp until December 7, 2006 when Goldcorp's sale of 18 million shares reduced its ownership to 48%. On February 14, 2008 Goldcorp divested itself completely of Silver Wheaton, selling 108 million