Datolite - Encyclopedia

    Class : Silicates
    Subclass : Nesosilicates
    Crystal system : Monoclinic
    Chemistry : CaBSiO₄(OH)
    Rarity : Uncommon

Datolite is a secondary boron silicate of hydrothermal origin. It is a mineral that owes its name to the Greek dateisthai (divide) and lithos (stone) because subjected to a shock the aggregates are easily fragmented. It is generally formed like zeolites and prehnite, in the cavities of basic magmatic rocks, but also as a hydrothermal alteration product in various metal deposits in basic context as well as in skarns and limestones subjected to the action of B-rich fluids. Datolite in developed and aesthetic crystals is rare and usually occurs as tabular crystals ; the mineral is more common in globular, columnar or radiate masses, of porcelain aspect. From vitreous to resinous, it is colorless or pale yellow-green, sometimes white or greyish, pale blue or pale violet. Because of its rarity in aesthetic crystallizations, it is a mineral little known by mineral collectors, it is also a mineral cut for jewelry, especially in cabochons.

In France, datolite is reported at Raon-l'Étape in the Vosges Department in the old quarry of the Pomme de Pin, Côte Saint-Dié, Col of Sainte-Marie-aux-Mines or Wisembach. According to the geologist Daubrée, datolite frequently carpets the druses of kersantites, very frequent in this granitogneissic massif.

No fake known for this species.