Page:Architectural Review and American Builders' Journal, Volume 1, 1869.djvu/716

 574 The Architectural Review and American Builders' Journal. [Mar., CRYOLITE. IX Number VII, p. 445, we gave an account of Hot-Cast Porcelain ; but were unable to obtain its chemical com- position, in time for the press. The omission is now supplied, in this short account of a very interesting, and, as will be seen, extremely useful mineral, called Cryolite, which, so far as at present known, is found, in merchantable bulk, only in a single locality, and that in the arctic regions. Near the southwestern point of Green- land — between Julianshaab and Frede- rickshaab, but nearer the latter, and a little to the northwest of Cape Desola- tion, in latitude 61° 13' north and longi- tude 44° west of Greenwich, on Arksuk Fiord, or Arsut Bay — one of those deep, rocky and winding inlets, which pene- trate, at intervals of a few miles, the mountain barriers of this dismal coast — is Ivigtut or Ivigtout, the point referred to, which is thus particularized, because it is not given in the Gazetteer, or upon any ordinary map. Here is a little Danish port, upon a fine open roadstead, for hyperborean regions. The neigh- borhood is exceedingly picturesque, the harbor being surrounded by lofty moun- tains, upon the flank of one of which, just behind and close to the port — so that the ore can be, and is wheeled, upon a short, circuitous, elevated, graded, wooden way, from the mouth of the mine to the deck of the ship — lies the deposite of Cryolite, a minei'al whose name is also spelled Kryolite, and, by the Danes, Kryolith, the signification be- ing ice-stone. The term springs from the Greek */>»<>£ [Ki^-os] frost or icy cold, and y^"s [Lithos] stone. This designa- tion arises from the mineral being, like ice, readily fusible in the flame of a can- dle ; but as it comes from the region of perpetual frost, and in color and general appearance much resembles snow and certain forms of ice, the name is trebly well chosen. This substance is gene- rally, in bulk, of a very pure white, alihough it is found of many hues, even to a dark brown ; and, while the abso- lutely pure specimens are of translucent white, something like pure selenite, manj' of the richer pieces, assajdng over eight}' per cent, of Cryolite, are quite dark in color. According to James D. Dana : The primary crystalline form of Cryolite is a right rectangular prism, with cleavage perfect parallel to its ends, or, in other words, in the plan corresponding with the exact transverse section ; and less so parallel to the lateral, or longitudinal, faces of the crystal. Streak white, color white, sometimes reddish or brownish, sub-transparent; translucent. Immer- sion in water increases its transparency. Brittle. First scientifically discovered by Giesecke, in two veins in Gneiss. Cryolite occurs at Ivigtut, or, as it is often called, Ivigtuk, in a surface vein eighty (80) feet thick, and other- wise of indefinite extent, consisting al- most entirely of pure Cryolite, the excep- tional minerals, in small quantities, being the sulphurets of iron and copper, the sulphuret of lead, or "galena," crys- tallized carbonate of iron, or spathic iron, and a few others. Cryolite is a double fluoride of aluminium and sodium, its chemical analysis showing : Fluorine, ... 54. Aluminium,. ^13. Sodium,. . . 33. 100. The mineral is found in solid masses, penetrating, on one side, the rocky ridge, at an angle of forty-five degrees, and on the other descending into the depths of the ocean. The shores of this coast are so precipitous, that vessels fastened to the land by the bow, have scarcely soundings, at the