Without question, this specimen of sodium, copper, sulphate from Chile, exhibits the most intense teal blue color I have ever seen in a natural mineral specimen. It displays what is classic for the species, lamellar growth of crystals in parallel bundles. What is more unusual are the terminated small crystals, to .25 cm across, at one end perched on the terminations of the larger crystals. The closest color to this can be found in the post mining crystals of melanterite and chalcanthite. A very beautiful specimen from a long-defunct locality which has also produced the best of this species (and is the type locale as well) 6.2 x 3.3 x 2.2 cm