Azurite and Malachite from the Liu Feng Shan Mine, Anhui Province, China
What is Azurite?
Azurite is an extremely popular mineral species because of its distinctive, attractive color - a rich, deep blue called "azure blue". Powdered azurite has been used by humans for eons as a coloring agent in paints and dyes. Azurite is a Copper Carbonate Hydroxide which occurs as a secondary mineral within the oxidized zone of copper ore deposits. Azurite is often associated with and occasionally replaced by the attractive green Copper Carbonate Hydroxide mineral known as malachite. Chemically, while both azurite and malachite are the products of the oxidation of copper deposits, malachite has undergone more oxidation than azurite. This means that malachite represents a later stage of oxidation and the increased oxidation is the cause for the color change from the azurite-blue to malachite-green in these two very similar copper carbonates.
Azurite (and Malachite) are Monoclinic. Perhaps, most sought after by collectors are azurite crystals occurring as sharp, lustrous, prismatic, azure-blue to blackish-blue crystals which can be transparent in very thin crystals to transluscent or opaque. Azurite, however, occurs in a variety of crystal habits. Azurite forms as prismatic crystals, tabular-bladed crystals with wedge-shaped terminations, as aggregate crusts or radiating crystal masses, or as botryoidal, nodular and earthy masses.
Liu Feng Shan Mine, Anhui Province, China
Over the past several years, a sizeable number of very spectacular azurite/malachite specimens have been produced from the Liu Feng Shan Mine, an operating copper mine in Anhui Province, China. The Liu Feng Shan mine (meaning in Chinese "six tops of mountains mine") has been in production since the early 1970's. The mine property includes fairly sizable complex of mine headquarters buildings, an adjacent open-pit, several mine shafts, and waste dumps. The open pit has been abandoned for sometime now and these recent, beautiful azurite/malachite specimens have come from the series of three (likely interconnected) vertical shafts. Underground the conditions are very challenging, as the deposit is hosted in a thick breccia zone invested with some of the most damp, sticky, red/brown fault gouge and clay imaginable. However, locally firmer areas of limonitic goethite do exist, and it is within these firmer areas that vugs lined with velvety-green malachite and sharp,lustrous deep blue azurite occur.
Buying Tips
Azurite and malachite specimens from the Liu Feng Shan mine bear a striking resemblance to the gorgeous azurite/malachite specimens from the classic copper mines at Bisbee, Arizona. One would expect the best of these Chinese specimens to become treasured classics in the years ahead. Buyers for the Collector's Edge Minerals, Inc. have visited the Liu Feng Shan mine on several occasions and make the observation that the production of mineral specimens from the mine will likely not continue for much longer, at the most a few years time.
Individual crystals of Azurite larger than 1 cm on edge are unusual for the Liu Feng Shan mine. The azurite and malachite crystallize on the walls of small vugs within the limonitic goethite. These vugs typically range in size from that of a golf ball to that of a basketball. What makes these specimens so special is that the azurite forms as fantastic "carpets" of sparkling. medium-to-dark blue crystal druses on the walls of these vugs. Occasionally, a layer of vibrant green malachite creates a wonderfully contrasting backdrop for these small, sparkly azurite crystals.
