Abstract
The Synthesis of Opalin Materials Takajiro Shimohira, Tsutomu Hiroshima: National Institute for Researches in Inorganic Materials, Sakura-mura, Niiharigun, Ibaraki Opalin materials which show some of the characteristics of natural precious opal have been synthesized. The process of making the materials was as follows;1) Monodispersed suspensions of spherical silica particles of colloidal size were produced by means of hydrolysis of ethyl silicate.2) An ordered close-packed array of hydrated silica particles has been achieved by sedimentation over a period of several months.3) Sintering and impregnation method were used to harden the arrays of stacked spheres.
