In this video Mike compares turquoise of different grades from four different mines using Turquoise Grading Rules following the Robert's/Ryan system of turquoise grading to determine an R2 grade. The rules are detailed in the previous article on turquoise grading. Grading from a photo is difficult and a grade may not be determined without seeing the actual stone but for the purposes of this exercise all viewers are operating under the same limitation. Grades posted in the comments of the first grading video were lower than the grades assigned from seeing the stone. Please try your hand at grading and post your results in the comments. Also note that the Gem Grade cab shown as King Manassa is actually Royston.
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