There isnt a specific grade called Indian Creek Slate. The grading of slate typically depends on its quality, with higher grades being more durable and less likely to flake or chip. The grades usually range from A to C, with grade A being the highest quality and grade C being the lowest. Different quarries and suppliers may have their own grading systems, so it is best to check with the specific supplier for more information on the grade of Indian Creek Slate they offer.