This is a complexly intergrown mass of crystallized atacamite, in huge crystals unlike any I have seen from Chile. It is 100% crystals, some damaged and contacted, and some not. I have never myself seen another specimen from this remote copper mine located 170 km SE of Iquique. Discovered over 200 years ago and sent back to Europe for study, atacamite was named from this region's specimens. NOTE that this is thought to be the specific mine locality for the species (though usually the type locality is given simply as "in the Atacama Desert.".. see IMA list of type specimen locations) .