Pectolite: Gemstone Information

Pectolite: Gemstone Information Pectolite is NaCa2Si3O8(OH) and a member of the wollastonite mineral group in which it forms a series with sérandite (q.v.) whose Mn is borrowed to provide shades of pink in an otherwise colourless, white or grey mineral. Pectolite occurs most commonly as translucent globular masses, the rarer crystals showing tabular habit of the monoclinic or triclinic system. There is a perfect cleavage in two directions.The hardness is 4.5–5 and the SG 2.84–2.90. The RI for the alpha, beta and gamma rays is 1.592–1.610, 1.603–1.615 and 1.630–1.645, biaxial positive with a birefringence of 0.036. Usually a spot reading of 1.60 is obtained. Pectolite may show orange-pink fluorescence under LWUV (material from Bergen Hill New York, USA) and a yellow fluorescence with green phosphorescence (Paterson, New Jersey, USA). Massive pectolite coloured a strong blue may be offered as a turquoise substitute under the trade name Larimar. This material comes from the Dominican Republic. Pectolite occurs in nepheline syenites and fine crystals (colourless, light pink and yellowish brown) are found at Mt Saint Hilaire, Quebec, Canada, and from the Jeffrey mine,Asbestos, in the same province. This location produces fine pale green prismatic crystals. Pectolite from Alaska has been offered as a jade simulant.