I’m thinking about entering a stone in the Novice competition and understand they use 10 x magnification to grade the stones.I use a 3,5 magnification headset to cut and polish a stone,and have found the polish looks good under 3.5 x magnification,but when inspecting the polish with a 10 x loop I can still see minor scratches on the facet surfaces. Will this affect the grade I get on the finished stone? In other words, does the final polish have to look flawless under a 10 x loop to be considered good?
Scratches will certainly affect your score, but they are not the only criterion. You might want to study the sample judging sheet for a better idea of what the judges are looking for.