Avoid "windowing" (where you can see through the stone's center) or "deep bellies" that hide weight without adding visual size. Variable
Prices per carat increase exponentially with size. For example, a 10ct unheated vivid blue stone can exceed $50,000. Sapphire 4Cs | Determining Value in Sapphires buy blue sapphire stone online
Look for medium to medium-dark tones with vivid saturation. Pure blue commands a premium over stones with secondary green or purple tints. Medium Avoid "windowing" (where you can see through the