Pectolite - Encyclopedia

    Class : Silicates
    Subclass : Inosilicates
    Crystal System : Triclinic
    Chemistry : NaCa₂Si₃O₈(OH)
    Rarity : Uncommon

Pectolite forms an isomorphic series with serandite, its manganiferous equivalent, the intermediate terms being called schizolite. It owes its name to the Greek pêktos (compact) and lithos (stone) in reference to its structure. It is a late mineral of nepheline syenites, also common in the cavities of basalts and dolerites where it accompanies zeolites. Pectolite is also known in serpentinites and peridotites of ophiolitic complexes ; it is frequently associated with prehnite, datolite and different zeolites. Pectolite commonly occurs as acicular crystals (up to 15 cm), rarely completed and grouped into radiated bundles or fibroradiated urchins. Large prismatic crystals are much rarer. Its luster is pearly to vitreous, it is mostly colorless to white, sometimes gray, greenish or yellowish, it is called larimar when it is blue and massive. This last blue variety is very appreciated in jewelery and is exclusively extracted from Dominican Republic. Finally, compact white pectolite was used as materials for the manufacture of weapons of war by Alaskan Thlinkit Indians.