Callaghanite: A Rare Find

     Callaghanite is a very rare mineral that is composed of magnesium and copper. Callaghanite crystals are very small, usually less than a millimeter in size, and I have read that they are pseudo-octahedral or dipyramidal in shape. Unfortunately I am not well-learned in the subject of geometry so I do not know much of what those names mean. I cannot describe the exact shape of a callaghanite crystal based upon my own observation because I have never seen one under a great enough degree magnification. Callaghanite crystals are often found as incrustations (they form a crust on another rock or mineral) or as veins in rocks. Callaghanite crystals are azure-blue in color. By the way this color is not caused by impurities, callaghanite crystals are naturally blue. I have personally observed callaghanite specimens to sparkle a great deal when tilted and moved about under a light. Callaghanite is named for the American Mineralogist, Dr. Eugene Callaghan.
     Because callaghanite is so rare there are no real uses for the mineral outside of collecting. It is not used as a gemstone because its crystals are far too small. In theory callaghanite could serve as a source of copper or magnesium, but it is far to rare to justify its mining for that purpose when there are other, more abundant sources of the metals available.
     Being an extremely rare mineral callaghanite has few sources. Callaghanite can be found in Nevada, Oklahoma, Austria, and Italy.
     Callaghanite is arguably the rarest mineral in my collection. I am quite thankful to have such an uncommon specimen and I hope that you can manage to acquire some as well!