Cool School Sections Cool School Home 4C's Main Page 4C's Cut 4C's Proportion 4C's Optical Symetry 4C's Determining Round 4C's Clarity 4C's Girdle 4C's Naturals       Fluorescence When a diamond is exposed to short- or long-wave ultraviolet light, it will sometimes radiate different colors of light or "fluorescence". If you purchase a certified diamond the level of fluorescence will be listed on the certificate. The most common color is blue and many years ago the term "blue-white" was used to describe diamonds with intense fluorescence that was visible in normal daylight. Moderate fluorescence will have little or no effect on its value however, some diamonds with very intense fluorescence will appear milky even without the ultraviolet light. When considering a diamond, a rating of Faint or Medium should not be a concern. Laser Drill Holes For twenty five-years, laser-drilling has been used in the diamond industry to remove black, carbon-filled inclusions from diamonds. The process includes drilling a hole down to the black inclusion with a laser. The stone is then placed in an acid solution which burns out the black material from the inclusion. Although, the stone's appearance has been improved, you now have a diamond with a hole drilled into it and if the black inclusions were many, you have several holes. There is no question that this treatment affects a diamond's value but here is where it gets difficult. According to current guidelines set forth by the Federal Trade Commission, jewelers do NOT have to disclose this treatment to consumers. In 1996, they determined that laser-drilling is a permanent treatment that does not create a special care requirement and that a reasonable consumer acting under reasonable circumstances should be able to ascertain that the stone has been treated.