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Diamond Selection – 4C’s and an F

The Truth About Diamond Fluorescence

Diamond buying is hard enough. First you have to understand the 4C’s, and then you have to try to judge if diamond certifications are accurate. So, adding one more aspect to the decision making process is too much for some people. But then, here comes fluorescence. The natural response is to keep it simple: if it has fluorescence it’s bad, and if it doesn’t it’s good. Unfortunately, simple does not work here.

What is fluorescence? Fluorescence is a form of lumination that is created when a diamond is exposed to low or high wave ultraviolet light. Some degree is common in nearly one half of all diamonds. One major point in understanding ultraviolet light is sun light is a strong source of ultraviolet light. Therefore, when a diamond is outside in the sun light, the impact of fluorescence will be noticed.

Fluorescence: the good, the bad, and the inconsequential

The bad news is that sometimes fluorescence can make a diamond look foggy or waxy as some people describe it. Most people don’t want a hazy looking diamond that loses some of its fire in the sunlight. The good news about fluorescence is that sometimes it can actually improve the appearance of diamonds by improving its color grade in the face up view (which is the way most people see their diamond in jewelry). So, a fluorescent diamond that is actually J color can look like it is H color (for more info on color grades and the 4C’s see our Diamond Buying Guide). The kicker is that sometimes, fluorescence has no visible effect on the diamond quality at all. So, is fluorescence bad or good? Unfortunately, it’s not that simple. Each diamond is unique and will react differently when exposed to ultraviolet light. So, don’t let anyone tell you that fluorescence is always bad or always good. Now, you know better.

Just one final thought, the Hope Diamond fluoresces red and it is a very beautiful diamond.

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