Do Diamonds Glow Under Black Light?

Do Diamonds Glow Under Black Light?

Diamonds are beautiful, charming, and precious stones to many around the world. Mostly loved for their glitter and brilliance properties when exposed to bright light. One other property that is less popular to most is the diamond's ability to glow under black light (UV light). On average, 30%-35% of natural diamonds glow when they interact with UV light. 

What Causes Diamond to Glow Under Blacklight

Diamonds' glow under black light is attributed to their fluorescence property. Diamonds emit visible light when exposed to UV  light from a fluorescent lamp. Fluorescence occurs when the chemical in a diamond's crystalline structure absorbs and re-emits energy from fluorescent lamps as visible light.

Some diamond structures also contain elements such as boron, nitrogen, or aluminum. When exposed to UV light, the energy from the UV light is absorbed by these elements' electrons which then react back causing a glow.  

Do Diamonds Glow Under Black Light?

Types of Diamond Fluorescence

Diamonds can emit glows differently in terms of color or color intensity under black light. The type of diamond fluorescence depends on the purity of the diamond and how strong or intensely a diamond interacts with UV light. Diamond fluorescence type will mostly be identified in a lab during diamond certification.

Pure natural diamonds produce a blue glow when exposed to UV light. The variation of the blue glow depends on how the pure natural diamond interacts with the UV light. Below are five types of fluorescence from pure natural diamonds.

  • None fluorescence- Diamonds with a negligible blue glow
  • Faint fluorescence- Diamonds with a very slight blue glow
  • Medium fluorescence- Diamonds that have a medium blue glow
  • Strong fluorescence- Diamonds with a strong blue glow
  • Very strong fluorescence- Diamonds with a very intense blue glow

On the other hand, impure natural diamonds contain impurities that trigger different color-type glow when exposed to black light including:

  • Green glow
  • White glow
  • Red glow
  • Yellow glow 

Is Diamond Fluorescence Good or Bad

Well, whether diamond fluorescence is good or bad depends on personal preferences.  Diamond fluorescence has the following impact on a diamond stone:

  • Reduced price- On average diamond fluorescence may cause a value reduction of between 15%-18%. If you do not mind cheap diamonds you can go for a diamond with fluorescence. 
  • Improves color- Sometimes fluorescence in a diamond enhances its color by reducing yellowness.
  • Cause haziness of a diamond- Very strong or intense fluorescence might make a diamond look hazy and cloudy. It is advisable to avoid such diamond stones. 

If you are looking to procure diamond stone jewelry with specific properties such as fluorescence type, it is wise to consult an expert. Do not hesitate to contact Luvari for all your jewelry needs. We guarantee high-quality and affordable jewelry pieces customized to meet your preferences. 


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