What Makes A Diamond Sparkle?

What Makes A Diamond Sparkle?

When it comes to sparkling, diamonds are the most coveted gemstones known to man. For diamonds, all other qualities that make gemstones valuable are often ignored in favor of those that enhance their sparkle. So, while the monetary value of diamonds rests heavily on their size, it's their dazzling sparkle that captivates us most. Of course, there are many things to love about a beautiful diamond, but what is it that makes a diamond sparkle?

What Affects The Amount Of Sparkle In A Diamond?

A diamond's sparkle is the result of the stone's interaction with light. While the color and clarity have a minor impact, the quality and type of cut primarily determine how a diamond will react to the light that surrounds it. While a bigger diamond may be more dramatic, it's the proportions of the stone, with respect to the angles and measurements of its facets, that creates the dramatic effect you see when light strikes a perfect diamond. Often a slightly smaller diamond of better cut will be more impressive than a larger one that does not perform the same optical “magic.”

When light enters a well-cut diamond, it enters the top and moves towards the bottom, and the density of the diamond slows the light to less than half its normal speed. As it moves through the diamond, the light is reflected back and forth off the stone's facets before being redirected through the top and to the viewer's appreciative eye.

Gemologists who have studied the interaction between a beautifully-cut diamond and light attribute the stone's sparkle to three optical effects: 


There are two components of brilliance: internal and external. Step-cut diamonds (such as baguettes  please add link to other blog here), only have external brilliance--the light that bounces off the facets on the diamond’s exterior. But brilliantly-faceted diamonds, which accounts for the lion’s share of diamond, also exhibit internal brilliance, which is the light that bounces around inside the diamond, to eventually exit. The combination of a diamond’s internal and external brilliance is described as brilliance. Brilliance is the quality that gives the diamond its brightness and makes it appear as if it's lit from within.


Some of the white light that enters a diamond is broken up into the spectral hues that comprise white light. Each hue is bent at a different angle, and therefore you can view the colors individually. This splitting and bending of white light into the spectral colors is called fire. Fire is the red, orange, yellow, green, blue, and violet, reflecting from your diamond like a prism.


Scintillation is the optical effect that causes your diamond to sparkle or flash as you and your ring move through the light. Scintillation changes with the light and as you move, creating a dynamic and dazzling effect. In general, the smaller facets on a diamond are the ones that cause scintillation. This is part of the reason why diamonds above a certain weight are more often found in non-round (“fancy”) shapes--because those shapes have areas where there are smaller facets, thus increasing the scintillation.

Need Help Finding A Diamond That Will Sparkle?

 At Alara Jewelry, we are diamond experts. Whether you need an engagement ring, anniversary gift, or a custom piece of jewelry, our team of gemologists can help. We have the selection and styles that you are looking for--and probably a lot of styles you never knew existed. But our commitment to customer service puts us in a class of our own. Contact us today to learn more about how we can help you find the perfect diamond for any occasion.

Want to learn even more about selecting a diamond for an engagement ring or other special gift? Download our Free Engagement Ring Buyers’ Guide


  • Tonja

    @GertrudeOchowa You’re welcome! Glad you found it useful. Let us know if we can answer any specific questions for you. You can always use the chat in the lower right hand corner, or text or call us at 406-522-8844. We’re open 7 days a week.

  • Gertrude Ochowa

    Good information. Thanks.

Leave a comment

Please note, comments must be approved before they are published