Diamond Fluorescence explained
What is Fluorescence in a Diamond?
Diamonds that receive low Fluorescence grades tend to emit a gentle glow when exposed to UV light, like sunlight. This glow can sometimes give the diamond a hazy appearance. This hazy effect may offset the advantages of a high Cut and Colour grade. Therefore, diamonds with no Fluorescence are typically preferred.
Diamond Fluorescence scale
Diamond fluorescence is assessed using descriptive terms that indicate the intensity of fluorescence. The Gemological Institute of America (GIA) classifies diamond fluorescence into five grades:
- None: This means the diamond exhibits no fluorescence.
- Faint (Faint Blue): In this case, the diamond displays minimal fluorescence.
- Medium (Medium Blue): The diamond has slightly noticeable fluorescence, which can result in a hazy appearance in sunlight.
- Strong (Medium Blue): For diamonds with noticeable fluorescence, which can make them appear hazy in sunlight.
- Very Strong (Very Strong Blue): Diamonds with significantly noticeable fluorescence, resulting in a very hazy appearance in sunlight.
The grading process involves comparing the diamond's fluorescence to master diamonds of different fluorescence grades until a match is found, helping to determine the appropriate grade. These grades offer insights into the level of fluorescence present in the diamond, with some people preferring diamonds with little to no fluorescence to maintain clarity and sparkle.
Is Fluorescence a characteristic found in all diamonds?
Fluorescence is not a universal feature in diamonds; approximately 30% of diamonds exhibit fluorescence. Therefore, it is entirely feasible to discover a diamond without fluorescence for your ring or jewelry. The general consensus among most gemologists is to prioritize diamonds with either no fluorescence or, at most, extremely minimal fluorescence.
Is Fluorescence positive or negative?
The evaluation of diamond fluorescence can be both positive and negative, and this assessment depends on the specific characteristics of the diamond, particularly its color grade. In diamonds with higher-quality color grades, fluorescence is often considered less desirable. When exposed to ultraviolet light, such as sunlight, these diamonds may emit medium or strong blue light, potentially giving the diamond a hazy appearance. However, in diamonds with lower colour grades, the blue light emitted by fluorescence can sometimes offset the yellowish tint of the diamond, making it appear more balanced. For diamonds graded I to M in color, a certain level of fluorescence can be advantageous, although it may cause the stone to appear hazy in sunlight.