George W. Fischer

The prime requisite for coloration of gemstone is that it be porous . That is to say there must be...

There are several reactions well known to chemists, involving iron compounds and prussiate compounds (ferrocyanides and ferricyanides) that yield characteristic...

The use of cobalt compounds to impart blue hues to glass, glazes and enamels has been known for centuries. "Cobalt...

Various and attractive shades of blue can be induced in gemstone by the use of copper compounds. This is perfectly...

The most important detail in the preparation of gemstone for chemical coloration is that it be clean. Oil and grease,...

There are only two ways that I know of to induce black into gemstone. One of these involves carbon while...

There are only a few inorganic processes, in my experience at least, that will impart pinks or reds to gemstone....

At first consideration, it might seem poor organization to include browns and yellows in the same chapter. However, I do...

It seems that everyone likes the greens in chemically colored gemstone. Probably this is because greens are almost universally pleasing...

This book is the culmination of some twenty-five years of personally supported research on the use of inorganic chemicals to...

Since the discovery that the principle of electrochemical displacement of metals can be used effectively and easily to induce inclusions...

Dendrites, moss, plume and similar inclusions have added interest and value to gemstone for about as long as man has...

Tin inclusions can be induced in agate and other gemstone varieties in much the same way as with copper. Just...