Metallography of the Precious Metals*

Special metallographic procedures are presented which produce flawless photomicrographs of the precious metals and their alloys. In addition to conventional metallographic techniques, special commercial and automated apparatus are described which greatly facilitate the metallography of metals such as ruthenium and osmium. Finally, a series of photomicrographs of alloys rich in the six platinum group metals, silver, and gold is presented demonstrating the techniques described as a comparative guide for the metallographer.