Fluorescence: should you worry?
Usually no. When fluorescence matters, and when it doesn't.
Fluorescence is a glow, usually blue, that some diamonds show under ultraviolet light. About a quarter to a third of diamonds have some. Faint and medium fluorescence can't be seen in normal light. Strong blue can even make an I or J stone look whiter. Very rarely, a strongly fluorescent stone looks slightly hazy in sunlight, which is why seeing the actual stone matters. Fluorescence does not tell you whether a diamond is natural or lab-grown, because both can have it. The certificate lists it, and our gemologist checks it on the video.
Choosing a diamond? Our diamond buying guide gives the cut, colour and clarity numbers to look for by shape and size.