Explanatory notes
… described below, or from ammonium alum. It is a light white powder, insoluble in water, specific gravity about … and synthetic precious or semi‑precious stones (rubies, sapphires, emeralds, amethysts, aquamarines, etc.), as a … to Chapter 76). The dry hydroxide is an amorphous, friable white powder, insoluble in water; when damp it is in …