Chuquicamata is one of the most strange copper deposits in the world, and produces not only a huge wealth of copper for industry but also a suite of incredibly beautiful rare mineral species of which the most classic is Krohnkite, a sodium copper sulfate (historically and mostly 100 to about 50 years ago) Chuquicamata, or "Chuqui" as it is more familiarly known, is by excavated volume the largest open pit copper mine in the world, located in the north of Chile, at 2850 meters above sea level. Specimens like this probably came out, I have assumed from old collections and labels, between the late 1800s and 1960 with mine managers from USA and Europe, who worked there. This is a rather large, and aesthetic specimen. The krohnkite occurs as vein fillings, and most often looks like this, with constrained crystals completely filling a vein space between layers of the host rock. Small bits of green color are included microcrystals of natrochalcite. Number 60 in the Halpern collection, acquired by the mid-1960s in the earliest days of his collecting. Comes with a custom lucite base for safe, upright, ideal display.