Scapolite is a mineral with a hardness of 6 out of 10 on the Mohs scale of mineral hardness [?]. These Tetragonally structured gems are made of complex silicate, their full chemical compound being Na4Al3Si9O24Cl-Ca4Al6Si6O24(CO3,SO4).
Scapolite is a mixed crystal series, a complicated sodium calcium aluminum silicate group composed of calcium-rich meionite, and sodium-rich marialite.
It appears as yellow, blue, pink, violet, or colorless prismatic crystals with a tetragonal system, mostly surface-growing, with perfect cleavage. These crystals are usually in aggregates that are massive granular, long columnar, dense, with vitreous luster and poor cleavage.
Pleochroism for pink and violet crystals is dark blue or lavender to colourless or violet. Pale yellow stones show colourless to pale yellow.
Its physical properties are variable, since this is a complex isomorphous series with hypothetical end members marialite and melonite and intermediate member mizzonite. It is hard, light, with specific gravity increasing from marialite to melonite. It is translucent or transparent, often has strong fluorescence in ultraviolet light. It fuses easily to a blistered mass. It is soluble in hydrochloric acid, leaving silica.
It occurs in igneous and metamorphic rocks, also in the vicinity of iron-ore bodies; in crystalline-schistose rocks of the mica-schist, gneiss and amphibolite types; in metamorphosed limestone and skarns; and in some pegmatites and granulites.
Deposits are found in Burma, Brazil, Malagasy Republic, Tasmania, Bodenmais/Bayerischer Wald and Saualpe/Karnten (Germany), Kiruna (Sweden), Lake Superior (USA).
Crystals 50 cm (20 in) long are found at Rossie and Pierrepoint, New York (USA), and fine crystals at Renfrew (Ontario) and Grenville (Quebec) in Canada, and at Lake Tremorgio (Switzerland).
Transparent crystals occur in pegmatites in Minas Gerais (Brazil), and Malagasy Republic. It is also found in Val Malenco (Sondrio), and other places in the central Alps, in blocks at Mt. Somma, Pianura (Naples) and Elba (Italy).
Massive scapolite mineral from Ontario, Canada displays bright yellow fluorescence under LWUV (long wave ultraviolet) rays. Yellow specimens from Myanmar giving yellow to orange and some East African yellow stones a very bright yellow-green under LWUV.
Scapolite inclusions have been reported in massive hessonite from Maligawila, Sri Lanka, and also from Lelatema, Tanzania.
Some scapolite gems exhibit chatoyancy. An example is cat's-eye scapolite; a white, pink, or violet, distinctly fibrous variety of scapolite from Mogok, Myanmar (Burma), produces a cat's-eye effect, when cut en cabochon in the correct direction. This is mistakenly called "pink moonstone."
Dipyre is a variety of scapolite with the components marialite and meionite. Also called dipyrite or mizzonite
Wilconite is a pinkish red variety of scapolite.
Scapolite is also called wernerite.
It is often confused with amblygonite, chrysoberyl, and golden beryl.
Scapolite is named after the Greek word meaning "stick stone" describing its crystal habit. The other name, wernerite, refers to the German explorer.
Scapolite is a rare gem mineral often cut as pink or violet cat's eyes, or cut cabochon and faceted.
Some pink-violet scapolite can have a milky appearance and when cut cabochon can imitate moonstone.
It is of interest to scientists and collectors.