Turquoise Grading Part Three

Jan 21, 2022
1 min read

In our final video for our January turquoise grading month Mike looks at some very high grade dark web turquoise from three different mines and grades them using the Turquoise Grading Rules based upon the Robert's Ryan rules for turquoise grading to determine an R2 alpha/numeric grade. Try grading these yourself to see how your grades compare understanding that an actual grade may not be assigned from a photo.

Recent Posts

See All

Robert Begay Interview

Robert Begay is a young Dine artist who is making extraordinary jewelry. In this video he tells of his background, his artistic influences, his love of turquoise and we see some beautiful jewelry.

Bruce Mead Lapidary Instruction

Bruce Mead was the Bisbee Rock Man and he taught me how to cut turquoise. In this video he shows how to attach turquoise slabs to the doping stick for cutting. Its a bit rough but worth learning from

Unveiling the Origins of Turquoise

2 Comments

Rated 0 out of 5 stars.

No ratings yet

Unknown member

Jan 21, 2022

Hi Mike, in the video or at least on my screen (which has pretty good color), the color of all of these stones looks almost identical. I wonder if there's any value in having some kind of pantone index color or other reference color by which to help judge turquoise color. I know it's a little subjective, and some of the blues seem to have added depth, maybe due to silica content (the very best Bisbee blue does this, at least for some of my gem grade stones).

Any thoughts?

Unknown member

Jan 21, 2022

Replying to

You have identified the major weakness of this exercise. Turquoise may not be graded by a photo and the subtle differences in the different mines are lost in the video. For the Turquoise Grading Rules (TGR) to gain acceptance extensive guidelines must be developed. I have started these in the article on grading but they need to be expanded. Your suggestion of a color index is excellent perhaps with examples of different turquoise colors. I am working on Turquoise in America Part Three 1990-2020. When that comes out I may try to work more on the guidelines. Your recommendations are welcome.