How many of THESE have you seen around? Langite is a hydrated basic sulfate of copper, first noted in England in the 19th century, and named after the Viennese physicist V. von Lang. Specimens just are not around on the market. This one was purchased long ago from a dealer in Berkeley, California, and ended up in the Hauck Collection, along with lots of other rare minerals. 8.4 x 6.0 x 2.7cm