{"id":219,"date":"2026-08-05T17:49:03","date_gmt":"2026-08-05T17:49:03","guid":{"rendered":"https:\/\/maisonfacelis.com\/journal\/?p=219"},"modified":"2026-08-05T17:52:56","modified_gmt":"2026-08-05T17:52:56","slug":"how-diamond-light-performance-works-the-science-behind-exceptional-sparkle","status":"publish","type":"post","link":"https:\/\/maisonfacelis.com\/journal\/2026\/08\/05\/how-diamond-light-performance-works-the-science-behind-exceptional-sparkle\/","title":{"rendered":"How Diamond Light Performance Works: The Science Behind Exceptional Sparkle"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">Ask someone why a diamond is beautiful, and the answer is almost always the same:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>&#8220;Because it sparkles.&#8221;<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">While this may seem obvious, very few people understand <em>why<\/em> a diamond sparkles so brilliantly.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The answer is <strong>light performance<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In fact, professional diamond buyers often consider light performance to be the single most important indicator of a diamond&#8217;s beauty. A diamond may have excellent colour, exceptional clarity, and impressive carat weight, but if it cannot manage light efficiently, it will never display the brilliance that makes diamonds so captivating.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is why two diamonds with identical GIA grades can look completely different when placed side by side.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Understanding light performance allows you to evaluate a diamond based on what your eyes actually see rather than relying solely on numbers printed on a grading report.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">What Is Light Performance?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Light performance describes <strong>how effectively a diamond captures, controls, and returns light to the viewer&#8217;s eyes<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A well-cut diamond does not generate its own light.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Instead, it acts like an incredibly sophisticated optical instrument.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Its job is to:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Capture incoming light.<\/li>\n\n\n\n<li>Reflect it internally.<\/li>\n\n\n\n<li>Separate white light into spectral colours.<\/li>\n\n\n\n<li>Return as much light as possible back toward the observer.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The better a diamond performs this process, the more beautiful it appears.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">The Journey of Light Inside a Diamond<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Understanding light performance becomes much easier when you follow the path of a single beam of light.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Step 1: Light Enters the Diamond<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Light first enters through:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The table<\/li>\n\n\n\n<li>Crown facets<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">At this stage, the light begins slowing down because diamonds have an extremely high <strong>refractive index<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This property bends incoming light far more than most transparent materials.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Step 2: Internal Reflection<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Once inside, the light reaches the pavilion.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If the pavilion angle is correct, the light reflects internally from one pavilion facet to another.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Instead of escaping, the light remains trapped inside the diamond.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This process is called <strong>total internal reflection<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It is one of the key reasons diamonds sparkle so intensely.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Step 3: Light Exits the Diamond<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Eventually, the reflected light leaves the diamond through:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The table<\/li>\n\n\n\n<li>Crown facets<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">As it exits, it creates the three optical effects we recognise as sparkle.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">The Three Components of Light Performance<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Professional gemologists divide sparkle into three separate optical characteristics.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Understanding these helps explain why some diamonds appear far more attractive than others.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">1. Brilliance<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Brilliance refers to the amount of <strong>white light<\/strong> returned by the diamond.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It creates the bright flashes that make a diamond appear lively even from a distance.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A diamond with excellent brilliance appears:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Bright<\/li>\n\n\n\n<li>Crisp<\/li>\n\n\n\n<li>Full of life<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Brilliance is usually the first thing people notice.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">2. Fire<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Fire refers to <strong>rainbow-coloured flashes<\/strong> produced when white light separates into its individual colours.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">These flashes include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Red<\/li>\n\n\n\n<li>Blue<\/li>\n\n\n\n<li>Green<\/li>\n\n\n\n<li>Orange<\/li>\n\n\n\n<li>Yellow<\/li>\n\n\n\n<li>Violet<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Fire occurs because diamonds have a high level of <strong>dispersion<\/strong>, meaning they separate white light into different wavelengths much like a prism.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Well-balanced crown angles play a major role in producing attractive fire.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">3. Scintillation<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Scintillation describes the flashes of light and dark seen when:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The diamond moves<\/li>\n\n\n\n<li>The observer moves<\/li>\n\n\n\n<li>The light source moves<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">This dynamic sparkle creates the lively appearance people associate with premium diamonds.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Without scintillation, a diamond would appear static and lifeless.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">The Four Behaviours of Light<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Light entering a diamond can follow four possible paths.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Understanding them explains why some diamonds outperform others.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Reflection<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A small portion of incoming light reflects immediately from the surface.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This creates some initial brightness.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Refraction<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Most light enters the diamond.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Because diamonds have a high refractive index (approximately <strong>2.42<\/strong>), the light bends dramatically.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This bending helps keep light inside the stone.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Dispersion<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">As white light travels through the diamond, different wavelengths separate.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This creates colourful flashes known as fire.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Diamonds possess one of the highest dispersions among naturally occurring gemstones, contributing to their unique visual appeal.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Leakage<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Unfortunately, not all light remains inside.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If proportions are incorrect, some light escapes through:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The pavilion<\/li>\n\n\n\n<li>The sides<\/li>\n\n\n\n<li>Poorly aligned facets<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">This is called <strong>light leakage<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Reducing leakage is one of the primary objectives of precision diamond cutting.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Total Internal Reflection: The Secret Behind Diamond Sparkle<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Perhaps the most remarkable property of diamonds is their ability to trap light through <strong>total internal reflection<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Because diamonds have such a high refractive index, light striking the pavilion at the correct angle reflects internally rather than escaping.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Imagine standing between two perfectly aligned mirrors.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The reflections seem endless because the light keeps bouncing back and forth.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A well-cut diamond behaves similarly.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The pavilion facets continually redirect light until it exits through the top toward the observer.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is why pavilion angle is often considered the most important proportion in a Round Brilliant diamond.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Why Light Leakage Reduces Beauty<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Every ray of light that escapes is a lost opportunity for sparkle.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Light leakage reduces:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Brightness<\/li>\n\n\n\n<li>Fire<\/li>\n\n\n\n<li>Contrast<\/li>\n\n\n\n<li>Scintillation<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Even if only a small percentage of light leaks away, the overall appearance of the diamond becomes less lively.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Professional cutters therefore aim to maximise <strong>light return<\/strong> while minimising leakage.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">How Professionals Evaluate Light Performance<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Unlike colour or clarity, light performance cannot be fully described by a single number.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Instead, professionals use specialised optical tools.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">ASET (Angular Spectrum Evaluation Tool)<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">ASET images display where the diamond gathers light from different directions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Typically:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Red<\/strong> indicates strong direct light return.<\/li>\n\n\n\n<li><strong>Green<\/strong> represents lower-angle light.<\/li>\n\n\n\n<li><strong>Blue<\/strong> creates contrast.<\/li>\n\n\n\n<li><strong>White or black<\/strong> often indicates light leakage.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">A well-performing diamond displays a balanced distribution with minimal leakage.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Ideal Scope<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The Ideal Scope is a simpler tool designed specifically to reveal light leakage.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In a high-performing diamond:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Most of the image appears rich red or pink.<\/li>\n\n\n\n<li>Black areas represent healthy contrast.<\/li>\n\n\n\n<li>White areas indicate light leakage.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">This tool is particularly useful when comparing diamonds with similar grading reports.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Hearts and Arrows Viewer<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Although primarily used to evaluate optical symmetry, a Hearts and Arrows viewer also helps confirm the precision of the facet arrangement.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Diamonds with excellent optical symmetry often produce more balanced light performance.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Why GIA Doesn&#8217;t Give a &#8220;Light Performance Grade&#8221;<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Many buyers are surprised to learn that the GIA does not assign a separate light performance grade.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Instead, light performance is evaluated indirectly through the overall <strong>Cut Grade<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This means:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Excellent Cut generally indicates strong light performance.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">However:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Not all Excellent Cut diamonds perform identically.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Some proportion combinations return light more efficiently than others.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is why experienced buyers often examine ASET or Ideal Scope images in addition to the grading report.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Lighting Changes Everything<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">One fascinating aspect of light performance is that it changes depending on the environment.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Sunlight<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Produces intense brilliance and colourful fire.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Jewellery Store Spotlights<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Designed to maximise sparkle with multiple focused light sources.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This explains why diamonds often look spectacular in display cases.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Office Lighting<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Produces softer brilliance and more subtle fire.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A well-cut diamond continues to perform beautifully even under ordinary lighting.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Candlelight<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Creates slower, warmer flashes of light.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Diamonds with excellent fire often appear particularly romantic under candlelight.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Why Cut Determines Light Performance<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Every article in this series has pointed to the same conclusion:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Cut is the foundation of beauty.<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The most important measurements include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Table percentage<\/li>\n\n\n\n<li>Depth percentage<\/li>\n\n\n\n<li>Crown angle<\/li>\n\n\n\n<li>Pavilion angle<\/li>\n\n\n\n<li>Optical symmetry<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">These determine whether light:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Returns to the observer<\/li>\n\n\n\n<li>Escapes from the diamond<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">This is why many gemologists recommend prioritising cut before colour or clarity.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Common Misconceptions<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">&#8220;Bigger Diamonds Sparkle More&#8221;<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Not necessarily.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A poorly cut 2-carat diamond may appear less brilliant than a perfectly cut 1-carat diamond.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">&#8220;High Clarity Means Better Sparkle&#8221;<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Only to a limited extent.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Most inclusions in VS or SI diamonds do not significantly affect light performance.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Cut has a much greater influence.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">&#8220;Colour Determines Sparkle&#8221;<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Higher colour grades appear whiter, but sparkle depends primarily on light performance.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A well-cut G-colour diamond often outshines a poorly cut D-colour diamond.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Practical Buying Advice<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">When choosing a Round Brilliant diamond:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Prioritise:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Excellent or Super Ideal Cut<\/li>\n\n\n\n<li>Balanced proportions<\/li>\n\n\n\n<li>Strong optical symmetry<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Whenever possible, review:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>ASET images<\/li>\n\n\n\n<li>Ideal Scope images<\/li>\n\n\n\n<li>Hearts and Arrows images<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">These provide valuable insight into how the diamond actually performs rather than how it is simply graded.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Final Thoughts<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Light performance is the invisible science behind every beautiful diamond.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It is the reason some diamonds seem to glow effortlessly while others appear ordinary despite having similar certificates. By understanding how light enters, reflects, disperses, and exits a diamond, you begin to appreciate that true beauty is not determined by size or rarity alone\u2014it is created through precision.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Every exceptional diamond is the result of careful engineering, where angles, proportions, and craftsmanship work together to capture as much light as possible and return it to the viewer in a dazzling display of brilliance, fire, and scintillation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For buyers, this knowledge changes everything. Rather than judging a diamond solely by its Four Cs, you can evaluate the characteristic that matters most: <strong>how beautifully it performs in light<\/strong>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Key Takeaways<\/h1>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Light performance describes how effectively a diamond captures, reflects, and returns light.<\/li>\n\n\n\n<li>The three components of light performance are <strong>brilliance<\/strong>, <strong>fire<\/strong>, and <strong>scintillation<\/strong>.<\/li>\n\n\n\n<li>Total internal reflection allows diamonds to trap and redirect light efficiently.<\/li>\n\n\n\n<li>Poor proportions cause light leakage, reducing sparkle.<\/li>\n\n\n\n<li>ASET, Ideal Scope, and Hearts and Arrows viewers help professionals evaluate light performance.<\/li>\n\n\n\n<li>GIA does not assign a separate light performance grade, making proportion analysis especially important.<\/li>\n\n\n\n<li>A diamond&#8217;s sparkle depends more on light performance than on carat, colour, or clarity alone.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Related Articles<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><em><a href=\"\/journal\/what-makes-a-diamond-sparkle\/\">What Makes a Diamond Sparkle?<\/a><\/em><\/li>\n\n\n\n<li><em><a href=\"\/journal\/ideal-diamond-proportions\/\" data-type=\"link\" data-id=\"\/journal\/ideal-diamond-proportions\/\">Ideal Diamond Proportions<\/a><\/em><\/li>\n\n\n\n<li><em><a href=\"\/journal\/diamond-crown-angle-explained\/\">Crown Angle Explained<\/a><\/em><\/li>\n\n\n\n<li><em><a href=\"\/journal\/diamond-pavilion-angle-explained\/\">Pavilion Angle Explained<\/a><\/em><\/li>\n\n\n\n<li><em><a href=\"\/journal\/hearts-and-arrows-diamonds\/\">Hearts and Arrows Diamonds<\/a><\/em><\/li>\n\n\n\n<li><em><a href=\"\/journal\/super-ideal-cut-diamonds\/\">Super Ideal Cut Diamonds<\/a><\/em><\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Ask someone why a diamond is beautiful, and the answer is almost always the same: &#8220;Because it sparkles.&#8221; While this [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[26],"tags":[],"class_list":["post-219","post","type-post","status-publish","format-standard","hentry","category-diamond-education"],"_links":{"self":[{"href":"https:\/\/maisonfacelis.com\/journal\/wp-json\/wp\/v2\/posts\/219","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/maisonfacelis.com\/journal\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/maisonfacelis.com\/journal\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/maisonfacelis.com\/journal\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/maisonfacelis.com\/journal\/wp-json\/wp\/v2\/comments?post=219"}],"version-history":[{"count":2,"href":"https:\/\/maisonfacelis.com\/journal\/wp-json\/wp\/v2\/posts\/219\/revisions"}],"predecessor-version":[{"id":222,"href":"https:\/\/maisonfacelis.com\/journal\/wp-json\/wp\/v2\/posts\/219\/revisions\/222"}],"wp:attachment":[{"href":"https:\/\/maisonfacelis.com\/journal\/wp-json\/wp\/v2\/media?parent=219"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/maisonfacelis.com\/journal\/wp-json\/wp\/v2\/categories?post=219"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/maisonfacelis.com\/journal\/wp-json\/wp\/v2\/tags?post=219"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}