CGC Pristine 10 vs Gem Mint 10: what's the difference?

CGC Cards has two 10 grades on its official grading scale. Pristine 10 sits above Gem Mint 10 and is meant for cards that look flawless even under magnification. A Gem Mint 10 allows the tiniest imperfections. PSA has a single top grade, PSA 10 Gem Mint. Because the scales differ, compare sold prices for the exact grade and company before deciding where to submit.

Full comparison: grading scales explained. Costs: PSA vs CGC.