Gemstones Blog

The following is a brief and exploratory study of a 3.87 carat yellow tourmaline I purchased from www.ajsgems.com Gems some time ago. The methodologies involved are non destructive and include microscopic testing as well as some imagery coupled with long wave UV testing. I thought I would share at least some of the more interesting pictures I obtained, and a few artifacts that threw me for a loop-but in a good way.

Yellow tourmaline is more or less a collectors stone, and anything particularly of gem quality of a carat or better is considered a collector size stone. The rough is often incredibly included, so there is little yield as a result. This study is meant to be a brief version of a more complete study of like kind that may or may not be published later on. These are simply the highlights and some things that are of interest.

I made the mistake of wiping the stone with a lotion containing tissue after rinsing it, hence why I could never get a good face up shot. It’s all dirty as a result, but it is remarkably clean for a yellow tourmaline-especially of this size. The polariscope without the polars crossed shows a slight pleochroism, but under various lighting conditions I have noticed a more obvious pleochroism within the stone. I can also tell you that it is uniaxial negative with a chronoscope, which is consistent with yellow tourmaline by pretty much any account I could find.

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