The mythical properties and symbolic potency attributed to jade (celestial stone) are stronger than those linked to almost any other stone. Whether it comes in deep green, shimmering white or enchanting violet, jade has for millennia been…
This compact self-contained screening device is designed to allow parcels of polished stones to be quickly analyzed to determine if they contain potential HPHT synthetics. PhosView cannot be used to screen for CVD synthetics simulants…
I’m hoping this series of articles will save some of you time, money, and embarrassment by discussing some of the common bench procedures that can easily lead to damage of colored stones – and how to avoid it. Some of it will be familiar,…
I’m hoping this series of articles will save some of you time, money, and embarrassment by discussing some of the common bench procedures that can easily lead to damage of colored stones – and how to avoid it. Some of it will be familiar, some…
Ever since childhood, I’ve been fascinated by rocks and gems. I started cutting cabs more than 40 years ago, and have been faceting colored stones for about 30 years. I do precision cutting of colored gems these days, and that often includes…
Foreign affairs – A well-known European dealer sells a 2.5-carat Möng Hsu ruby to a major jeweler in Europe. This jeweler then sells the stone to a Japanese client through their Japanese subsidiary. The client now takes the stone to a gemological…
Fluorescence is the emission of visible light from a substance under the stimulation of radiation of a shorter wavelength. It may be stimulated by (visible) light but most useful are blue light, short wave ultra-violet (UV) light, long wave…
Which is the best to buy: natural, enhanced, imitation, artificial or synthetic gems? The answer depends on how you plan to use it. Natural gemstones have not had anything done to them that changes their color.
Many gemstone owners enjoy wearing their treasures. Few things can ruin that enjoyment faster than the discovery of damage such as scratches, chips, or discoloration. Unfortunately, some damage is permanent. The good news is that proper…
This slim paperback book is a real addition to the book collections of the working jeweler, the jewelry shop owner, the gemologist and interestingly also to your customer, the general public. Wow! It is a compilation of straightforward information…
Historically gem possession has been reserved for wealthy, royalty, or high religious leaders. It has always been human nature to want what others possess, so imitation gems have been common for some 4,500 years, in the form of glass, plastic,…
A summary of the most common treatment techniques used on diamonds, how they are identified by trained gemologists, and what potential problems they present to manufacturers, retailers, and bench jewelers.
When the first warnings about color enhancement of golden South Sea pearls came out five years ago, fear struck the South Sea pearl industry. Some of the new enhancement methods for golden pearls were nearly undetectable, leaving dealers…
Can the colored stone industry choose a standard light source from the multitude on the market?
Since the beginning of time, man has sought to improve upon nature. Pearls are no exception. The majority of today’s cultured pearls have undergone some form of processing or treatment after their removal from the mollusk. The only way to confidently…
The prime requisite for coloration of gemstone is that it be porous . That is to say there must be spaces or vacancies into which the coloring chemical, in solution, can penetrate deeply in order to impart the desired color. These spaces are usually…
The use of cobalt compounds to impart blue hues to glass, glazes and enamels has been known for centuries. “Cobalt blue” glass is familiar to just about everyone. It seemed logical that cobalt compounds could be useful to impart color to gemstone…
Various and attractive shades of blue can be induced in gemstone by the use of copper compounds. This is perfectly logical, considering that several of our blue gemstone or mineral species owe their color to the presence of copper compounds.…
The most important detail in the preparation of gemstone for chemical coloration is that it be clean. Oil and grease, especially, must be entirely removed. I have found it practical to keep a bucket of detergent solution (ordinarily laundry…
There are several reactions well known to chemists, involving iron compounds and prussiate compounds (ferrocyanides and ferricyanides) that yield characteristic blue precipitates. All are applicable to chemical coloration of gemstone,…
The treatment and enhancement of gemstones has existed for centuries. Some enhancements improve on nature slightly, are undetectable, and they are permanent; this provides the gem market with a larger supply of beautiful gemstones. Other…
There are only two ways that I know of to induce black into gemstone. One of these involves carbon while the other is silver. Theoretically, there should be several other methods possible. I have tested these out however, and they have proved…
There are only a few inorganic processes, in my experience at least, that will impart pinks or reds to gemstone. These involve primarily four metals – cobalt, iron, mercury and silver. We already know cobalt can induce blue, purple, amethyst,…
At first consideration, it might seem poor organization to include browns and yellows in the same chapter. However, I do this because in some instances the same process imparts brown hues to some gemstone varieties and yellow to others. Admittedly,…
It seems that everyone likes the greens in chemically colored gemstone. Probably this is because greens are almost universally pleasing to the eye. No doubt this accounts for the great popularity of naturally green gemstone such as jade,…
This book is the culmination of some twenty-five years of personally supported research on the use of inorganic chemicals to induce color and inclusions in gemstone. Prior attempts to use dyes for gemstone colorations had proved very disappointing.…
Since the discovery that the principle of electrochemical displacement of metals can be used effectively and easily to induce inclusions in snakeskin agate, I have tried the method on several of the other gemstone varieties and have found…
Dendrites, moss, plume and similar inclusions have added interest
and value to gemstone for about as long as man has been aware of the
beauty and gem potential of such “rock”. But apparently up to now,
man has been dependent…
Tin inclusions can be induced in agate and other gemstone varieties in much the same way as with copper. Just as copper inclusions are made from copper chloride, so tin inclusions are made from tin chloride. Copper chloride imparts green and…
Beryllium diffusion typically brightens the color of ruby or sapphire, making a stone more yellow, orange, or red, depending on the original color. Because the color change can go all the way through the stone, the treatment is more difficult…
An old lapidary taught me an excellent trick for sealing cracks in gemstones. Some gems are inherently unstable. If a client of mine wants one of these gems for inlay, or to be cut or set, I will often use this technique – with full disclosure, of…
GIA recently released a video that provides an overview of lead glass-filled rubies and explains why it has begun to call them a “manufactured product” on reports. The video, which was created to educate the trade and public, also covers how…