Impressive, large, divergent and intergrown, medium to dark green prismatic crystals of atacamite to 2.5cm are preeminent on this specimen. The larger, dark green crystals of this copper hydroxychloride are well-terminated. This specimen is from early workings in the Moonta copper mines in the late 19th to early 20th centuries, around 1880-1900! It is almost impossible to obtain this material these days as they trickle out of old collections. U.S. National Museum (Smithsonian) and Lidstrom's labels accompany the piece for added significance. This is a fine, display quality miniature.