What is what does it mean if a diamond glows blue under uv light?

Diamonds that glow blue under ultraviolet (UV) light exhibit a phenomenon called fluorescence. Here's a breakdown:

• Cause of Blue Fluorescence: The most common cause of blue fluorescence in diamonds is the presence of nitrogen impurities within the diamond's crystal structure. When UV light strikes the diamond, these nitrogen atoms absorb the light and then re-emit it as visible blue light.

• Intensity Variation: The intensity of the blue glow can vary significantly from diamond to diamond. Some diamonds exhibit a strong, vibrant blue, while others show only a faint or negligible fluorescence. The intensity is typically graded as none, faint, medium, strong, or very strong.

• Effect on Appearance: Blue fluorescence can affect the appearance of a diamond, particularly in natural daylight.

  • In colorless or near-colorless diamonds (grades D-J), strong blue fluorescence can potentially make the diamond appear whiter or brighter, especially if it has a slight yellowish tint. The blue fluorescence counteracts the yellow, improving its overall perceived color.
  • However, in some rare cases, very strong blue fluorescence can make a diamond appear hazy or oily.

• Value Impact: The impact of blue fluorescence on a diamond's value depends on several factors:

  • Color Grade: For diamonds in the D-F color range, fluorescence generally has little to no negative impact on price and can even increase the value if it enhances the diamond's appearance.
  • Intensity: Very strong fluorescence may slightly decrease the price in higher color grades, while faint or medium fluorescence might not affect the price significantly. The potential negative impact of strong fluorescence is more pronounced in higher color grades, as any haziness it might cause is more noticeable in a perfectly colorless stone.
  • Market Preferences: Ultimately, market demand and consumer preferences can influence how fluorescence affects the value of a diamond. Some buyers actively seek out diamonds with strong blue fluorescence, while others avoid them.

• Identification: Blue fluorescence is a common and easily detectable characteristic that can aid in diamond%20identification. It can help differentiate between natural and some synthetic diamonds, though specialized gemological testing is required for definitive identification.

• Not All Fluorescence is Blue: While blue is the most common color of fluorescence in diamonds, they can also fluoresce in other colors, such as yellow, green, or orange, though these are rarer.