Cumengeite is a signature rare species from Mexico, and this is from the famous Type Locality at Santa Rosalia. The six-pointed star is the classic habit, and the color is a brilliant indigo-blue with high luster. Although seemingly small, this is really quite a nice and exceptionally sharp display specimen, and better in person. It is a thumbnail worthy of any sophisticated collection. These are from the famous late 1970s re-exploration of this prospect by Larson and Swoboda.