This venerable open pit copper mine has produced the finest specimens of krohnkite, a rare, hydrated, sodium, copper, sulfate. The rich, aquamarine color, translucence, good crystal form, all add to the collectability of this species. This is the single largest crystal I have ever seen, of this mineral. It is a large, translucent, complete crystal that is about ten times bigger than the norm. And those already are rare. Chuqui is one of the most significant localities for interesting minerals in the world, and sadly one of the most underappreciated in the hobby at large. Not only is this rare and significant, but it is beautiful enough to grace any shelf