An extraordinary and important old specimen of Brochantite from Chuquicamata, Ex Schortmann's and Immer Cook collection. The original label dates this to 1948-52, and by far it the best specimen I know of from this famed mine. This is certainly a serious contender for the best of specie outside of the 2016 Milpillas find. Even compared to the Mexican specimens this is a very significant stout cluster. The largest crystal is huge, 4.6 CM tall and quite thick. Close exam of the specimen finds a few slender needle crystals which are more typical of the specie. Under good magnification (40x) a few specks of blue that can be Krohnkite, Bellingerite or Aubertite etc are visible. There are areas of contacting making some rough edges but very little damage. A world class Copper secondary specimen.
Chuquicamata Mine, Calama, El Loa Province
6.3 x 4.4 x 4 CM (cabinet)
A superb very well crystalized example of this rare Copper Sulphate from Chuquicamata. Good Antlerite in prismatic crystals from this long ago find is not often available. These crystals are in the 3-4mm range which is about as large as any known from this legendary locality. Under magnification a variety of forms are noted and most of the individual crystals are well isolated, gemmy and brightly colored. This locale was at one time the source of many incredible rare copper minerals including rare copper Halides and what were for a century the worlds best Antlerites. A small newer find at Milpillas has since produced larger crystals with a different habit (and a far higher price). Chuqui was developed into one of the worlds largest open pits with efficient mechanized processes that now of course destroy any specimens at great speed. I have visited the site several times in the past decade but never found even a crumb worth obtaining, nothing is coming out. This piece is obviously from long ago.
Bright, large blocky habit Krohnkite crystals in a cluster with minimal matrix. From the type locale, Chuquicamata which is the only place where this rare Copper Halide was ever found in such fine crystals. While and non micro crystals are rare most of those are fibrous growths or slender clusters. Prismatic habits like this are far more uncommon, and were all found long ago. Most of the existing specimens were collected long before 1934 (the early 1900 era was most productive) but it is probable a few came out later. The zone where these were found was long ago disappeared, consumed by the largest open pit mine on the planet. Only seen now from old collections.