I found it!
I have located my copy of a simple user’s guide for the Refractometer that years ago was posted at either The British Gemological Institute or The Gemological Association of Great Britain; I do not remember which. There is no author listed. I remember, that it was taken down from the site shortly after I captured it.
I am preparing a two unit presentation to get faceters and gem enthusiast up to speed. The first is a U Tube video titled “Crystallography by Dave Woolley” that can also be found at the Lynchburg Gem and Mineral Society’s home site, under videos. It provides the visualizations necessary for the second presentation.
The second presentation will include a hands on version of the first and be titled “Useful Crystallography and Refractometry” to be given at the USFG Franklin Faceters Frolic, Saturday July 31 at 1 pm. Franklin, North Carolina, My text will get you up to speed for the Refractometer user’s guide. If I can not make it in person, I plan on making them available as hand outs. I expect that it will also be posted in the United States Faceters Guild, newsletter. I will try to include the Refractometer users guide in the newsletter if it meets copyright guidelines.
Hang on while I complete the second unit and get things sorted out.
Dave