A VERY unique assemblage, that also has two-sided aesthetics and a size significance that makes it stand out in any collection as an important piece. Benstonite is extremely rare worldwide and the best come from Illinois, I would say. This piece is a wildly different style of attractive and lustrous, deeply-colored benstonite perched to show off. Alstonite is a bonus, here. The shape of this specimen leads to the conclusion that a butterfly twin of calcite was replaced by the gray alstonite. Secondary growth of lustrous and translucent, amber colored benstonite coats large portions of the twinned crystals in an oriented fashion of overgrowth. Rare occurrence: Mined 1950's-1960's and from the Ross Lillie collection. Rcl#2338 (previously ex. Paul Harter and Dan Weinrich). Although not the most expensive thing, this is surely one of the more interesting pieces in the collection. It carries the special yellow tag marked as "museum reserve" which noted pieces under consideration for a deal to the Chicago Field Museum at one time.