Fluorescence is one of the least understood but most fascinating aspects of diamonds. People are often surprised to discover that some diamonds can glow or emit a faint glow under ultraviolet (UV) light. But how does this property affect the value and appearance of a diamond? In this article, we explain what fluorescence in diamonds is, how it influences their beauty, and what impact it can have on their market value.
What Is Fluorescence in Diamonds?
Fluorescence in diamonds is a natural phenomenon that occurs when a stone emits visible light when exposed to ultraviolet light. This glow is usually blue, although in rarer cases, it can be white, yellow, green, or red. This property is present in about 25-35% of diamonds and is considered a unique characteristic of some stones.
The intensity of fluorescence is classified into five levels:
- None
- Faint
- Medium
- Strong
- Very Strong
Most diamonds with fluorescence display a blue glow, which is complementary to the yellow color, potentially making certain diamonds with lower coloration appear whiter or colorless under ultraviolet light.
How Is Fluorescence in Diamonds Determined?
A diamond’s fluorescence is evaluated when the stone is exposed to long-wave ultraviolet light, commonly found in environments like nightclubs or even in direct sunlight. Gemologists determine the level of fluorescence by using specialized devices that emit UV light and observe the intensity of the glow.
An interesting factor is that fluorescence does not affect the diamond’s appearance under normal lighting conditions. It only becomes visible under UV light, so many people may own a diamond with this property without even noticing it.
How Does Fluorescence Affect the Value of a Diamond?
Fluorescence can have varying impacts on the value of a diamond, depending on the intensity of the fluorescence and the diamond’s color:
1. Colorless Diamonds (D-F)
In diamonds that are colorless or near-colorless (graded D, E, or F), strong or very strong fluorescence can decrease their value. This is because fluorescence can make the diamond appear milky or hazy under UV light. However, when the fluorescence is faint or medium, the impact on value is minimal or even nonexistent.
2. Yellow-Tinted Diamonds (G-J)
In diamonds with a yellow tint (graded G to J), blue fluorescence can be beneficial, as it counteracts the yellow and makes the diamond look whiter. In these cases, fluorescence can slightly increase the diamond’s value.
3. Fancy Color Diamonds
For fancy color diamonds, such as yellow or pink diamonds, fluorescence is typically not a major factor in value assessment. The rarity of the color generally carries more weight than fluorescence.
Myths and Realities About Fluorescence
There are several myths and misconceptions surrounding diamond fluorescence. Some believe that fluorescence is always negative, while others think it has no impact at all. Here are some key clarifications:
- Myth: “All fluorescent diamonds are of lower quality.” Reality: Fluorescence only negatively affects colorless diamonds with strong or very strong fluorescence. In some cases, it can enhance the appearance of diamonds with yellowish tones.
- Myth: “Fluorescence always makes a diamond look hazy.” Reality: Only diamonds with very strong fluorescence may appear hazy under UV light. Most diamonds with faint or medium fluorescence do not show this effect.
Tips for Buying a Diamond with Fluorescence
If you are considering buying a diamond with fluorescence, here are some tips to help you make an informed decision:
- Consider the Color: If you are purchasing a diamond graded G-J, blue fluorescence may be an advantage. If the diamond is colorless (D-F), it is best to avoid strong fluorescence.
- Examine It Under Different Lights: It’s advisable to view the diamond under various lighting conditions, including ultraviolet light, to see how fluorescence affects its appearance.
- Consult a Gemologist: A certified gemologist can give you an accurate assessment of how fluorescence impacts the diamond’s quality and value.
Conclusion
Fluorescence in diamonds is a fascinating phenomenon that can either enhance or diminish a stone’s beauty, depending on the diamond’s color and the intensity of the fluorescence. While many buyers avoid diamonds with strong fluorescence, in some cases, it can improve a diamond’s appearance. It’s important to consider how fluorescence affects both the value and aesthetics before making a purchase decision. For a safe purchase, always consult with a diamond expert and review the gemological certificate.
