A 1 carat blue sapphire may seem perfect to the unaided eye, but deeper inspection may uncover a whole other world. Natural sapphires frequently have inclusions, which are microscopic flaws that reveal the development history of the stone. These inclusions, commonly called "silk," can give the stone a little individuality and character. Excessive inclusions or fractures, however, might diminish the sapphire's durability and brilliance and lower its value. Reputable jewelers will make sure you understand the internal features of your 1 carat blue sapphire by providing a thorough clarity grade.