Pectolite is the calcium analogue of Serandite and is a member of the Wollastonite group of mineral species. Superb Pectolites are synonymous with the Jeffrey Mine of Quebec, as superb Serandites are synonymous with Mont. St-Hilaire. However, most are thin gand gracile. This kind of robust, textbook euhedral crystal is extremely rare! This cluster, dominated by the one large crystal, is every bit as good as you could hope for the species on a worldwide basis - I cannot think of another location which would produce such a stereotypic example, in fact. The main crystal is doubly-terminated (one excellent termination and the lower one partially contacted), and the Pectolite is gemmy to translucent. The luster is excellent, and the crystal has a shimmery satin appearance very much like Satin Spar. An excellent toenail or large thumbnail specimen - of a quality very difficult to find.