SYNTHETIC LAPIS-LAZULI AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To produce a synthetic lapis-lazuli assuming a color and a texture equal to those of a natural lapis-lazuli and having the same crystal phase as that of the natural lapis-lazuli. SOLUTION: This synthetic lapis-lazuli is synthesized by adding a pyrite having 40-1,000μm particle diameter to 100 mass % basic raw material comprising 10-90 mass % ultramarine, 5-60 mass % calcium carbonate and 5-85 mass % Portland cement and preparing a raw material so as to provide <=15 mass % amount of the pyrite and curing the resultant raw material with water.