The Make : Polish Diamonds are capable of taking a polish better than any other material on earth. This means that a diamond can be polished to have the most perfect, reflective surfaces. This is one reason why diamonds are known for their incredible brilliance. Grades for polish range from Ideal (which is very rare) to Excellent, Very Good, Good, Poor, and Fair. We consider Good polish to be the minimum for engagement rings. Please Note: Discounts for stones outside of these limits are too difficult to explain here. If you want to learn how to calculate a price for any diamond you want, please see my easy, fast, step-by-step Diamond Pricing Tutorial page. Back to: How to Read a Certificate