Carletonite is one of the very rare mineral species unique to the Poudrette Quarry at Mt. St-Hilaire, Quebec. This is a very colorful, lustrous, pretty blue cluster of crystals, highlighted by the 1.2 cm, stair-stepped, blocky crystal on top. There is a fragment of a 1.4 cm crystal on the side. While not quite the largest, these are very respectable bordering on huge for species and the quality is high. These came out in the late 1990s. A very respectable specimen from this unique find.