Use of Synthetic Quartz Crystals as a Support for Specimens in Powder Photographs

Abstract

IN the course of experiments on the hydrothermal growth of quartz crystals from aqueous alkaline solution by the temperature gradient method¹, thin needle-shaped crystals were obtained from the autoclave adhering to the cooler portions of the inside wall, to the bottom of the lid, and to the stainless steel support for crystal seeds. The autoclave was made of chromium steel, set vertically and heated from below. The solution contained 2 per cent sodium hydroxide and 3 per cent sodium carbonate by weight. The approximate temperature and pressure of the autoclave were 350–360° C. and 300 atm., respectively. The needles were obtained in large numbers pointing almost at random. The diameters of individual needles were uniform and ranged from 0.03 to 0.2 mm. Their lengths were 5 mm. or more. Typical examples are shown in Fig. 1.