One of the true classics of both Mexican minerals AND worldwide minerals both, for its unique style, these rounded, sparkling yellow spheres of mimetite only came out in one big pocket in the late 1960s (1969 if I recall). This unique find was brought to market by the late Benny Fenn, who sold most of them at the time for $4 per pound for the normal specimens. The fact that Al Kidwell, who knew Benny well and bought this in 1970s, paid $15, suggests this was one of the highgrade pieces at the time for the size and price range. On the back of his label, Al noted that he got a deal, and valued it at the premium of $25 immediately - this was actually big money for a Mexican mineral specimen in 1970. Mexican minerals seem always to have been priced more reasonably to market, than things from more exotic locations, and the 1970s was only just starting to see the rise in mineral prices that has expanded the market at the source and, to our benefit, brought out so many more pieces intact that otherwise would have been lost or destroyed. Here is a lesson in mineral pricing for you! This contemporary find was priced to liquidate a truckload at the time, as Benny thought he could just go mine more at this proprietary location where he had no competition. But, he sold out in the first year, and went back but never found more. Later, the prices on these have reached the point that the best larger pieces with the largest spheres do sell today for 6 figures regularly. The attractive isolation of the balls on the matrix says it all - and is the best contrast possible for a production where 98 percent were simply yellow masses. The brown matrix backing really elevates those few that have it, to another level.