This is a lovely specimen consisting small bluish COVELLITE crystals covering most of one side of a matrix of PYRITE crystals with some similar but much lesser COVELLITE on the other side from the Leonard Mine, Butte Mining District, Silver Bow County, Montana, USA. The specimen is 4.2 by 3.0 by 2.5 cms in size or about 1.68 by 1.30 by 1.00 inches and weighs 79.1 grams.