What Makes a Diamond Sparkle?

Welcome to a dazzling exploration into the world of diamonds, brought to you by Plateau Jewelers, nestled in the heart of Sammamish, WA. Today, we uncover the secrets behind the sparkle of a diamond, an allure that has captivated hearts and adorned royalty for centuries. Let's embark on this sparkling journey together, understanding what transforms a precious stone into a masterpiece of light and brilliance.

What Makes a Diamond Sparkle

The sparkle of a diamond, often referred to as its "fire," "brilliance," and "scintillation," is one of the most captivating features of this cherished gemstone. This luminous display is not merely a result of the diamond's composition but is primarily the outcome of precise cutting techniques that manipulate light in extraordinary ways. Understanding what makes a diamond sparkle involves exploring the interplay between light and the diamond's cut, shape, and clarity.

The Science of Sparkle

Cut Quality

The cut of a diamond is the most crucial factor in determining its sparkle. A well-cut diamond will have facets (flat surfaces) that are precisely angled and sized to maximize the reflection and refraction of light. When light enters the diamond, it is refracted, splitting into a spectrum of colors, and reflected from the interior facets like a mirror. The light that is reflected back to the observer's eye is what creates the appearance of sparkle or brilliance.

Facet Arrangement

The traditional round brilliant cut, with its 57 or 58 facets, is optimized for sparkle. Each facet must be precisely cut and aligned to ensure that light entering the diamond is reflected internally and directed back through the top of the diamond to the viewer's eye. The arrangement and proportions of these facets play a critical role in the diamond's ability to sparkle.

Refraction and Dispersion

Refraction occurs when light passes through the diamond and bends, slowing down as it moves from air into the denser diamond material. This bending of light is what allows a diamond to act as a prism, dispersing the light into its constituent colors, a phenomenon known as dispersion. The dispersed light exits the diamond, showing off the diamond's fire—the flashes of color that are seen.


Scintillation refers to the sparkle that is seen when the diamond, the light source, or the observer moves. This dynamic interplay of light and movement creates the shimmering effect that diamonds are famed for. Scintillation is affected by the diamond's cut quality and the arrangement of its facets, which can either enhance or diminish the sparkle.

Other Factors Influencing Sparkle

  • Diamond Shape- While the round brilliant cut is renowned for its exceptional sparkle, other shapes, known as fancy cuts (like the oval, marquise, and pear), can also exhibit significant brilliance and fire, depending on how well they are cut.
  • Clarity- Inclusions and blemishes can impact a diamond's sparkle by obstructing light paths within the diamond. A diamond with fewer and smaller inclusions (higher clarity) will generally sparkle more because there are fewer obstacles to interfere with the light.
  • Color- The color of a diamond can also influence its sparkle, albeit to a lesser extent. A diamond with less color (a higher color grade) will better allow the intrinsic sparkle and fire of the diamond to shine through, as there is less color within the diamond to absorb the light.


A diamond's mesmerizing sparkle is the result of a complex interplay between light, the diamond's cut, and its intrinsic properties. The precision of the cut is paramount, as it directly influences how light is absorbed, refracted, and reflected within the diamond, ultimately determining the intensity and quality of the diamond's sparkle. When choosing a diamond, considering the cut quality alongside clarity and color will ensure you select a gem that truly dazzles.

At Plateau Jewelers, we celebrate the union of art and nature, offering you a selection of diamonds that promise not just elegance, but a story of love, precision, and brilliance. Visit us in Sammamish, WA, and let us help you find a diamond that captures the light and reflects the brilliance of your own story.