Leightonite (exceptionally rare)

Item Description

Here we have an extremely rare specimen of Leightonite, a hydrated potassium calcium copper sulfate, found in only about 10 localities on Earth. This piece is from the type locality for the species, the famed Chuquicamata Mine in Chile, one of the largest mines in the world, and according to the entry on mindat.org, the largest open pit copper mine on Earth. Leightonite has been known since the 1930s, and was named after Tomás Leighton Donoso a Professor of Mineralogy at the University of Santiago, Chile, who lived from 1896 to 1967. Despite the fact that it has been known for close to a century, it is still incredibly hard to find, and the pieces from Chuquicamata (and the Salvadora Mine in Chile) are the finest examples ever found. This piece is an excellent and notably rich specimen filled with beautiful turquoise blue bladed crystals of Leightonite measuring to 2-3 mm, associated with minor dark green Natrochalcite on matrix. Under magnification, you can see the Leightonite crystals are distinct, well-formed and undamaged. A superb piece for any fan of rarities, copper species or minerals from the type locality.
Ex John Dagenais Collection.