What gives a diamond its sparkle?
The process of diamond cutting transforms a diamond and gives it sparkle. From an insignificant crystal in the ground, the true beauty of a diamond comes from the expertise of the diamond cutter.
The diamond-cutting process reveals the true hidden beauty of a diamond. From the rough crystal to the final faceted gemstone, the final result changes the passage of light passing through the diamond. At the same time, light reflects from the stone.
For this reason, diamonds provide the ultimate symbol of love. In fact, the diamond engagement ring has become the iconic symbol of love.
A significant part of a diamond’s value results from the cutting process. The cut and proportions of a diamond can influence value by as much as 40 per cent. For this reason, great time and effort go into cutting a diamond to release not only beauty but its value at the same time.
Most people refer to fire, brilliance and scintillation. But few people understand the difference between each of these terms.
In the following video, a round brilliant cut diamond sparkles with fire, brilliance and scintillation in a tension setting of our Unity ring design.
Light refraction and reflection in diamonds
The passage of light through a diamond slows as it passes through the matrix of carbon crystal.
Light bends as it passes from one medium to another—an effect referred to as refraction.
As this light travels through the diamond, it strikes another surface within the stone, and reflects white light back to the eye.
Cut grades and brilliance
The proportions and symmetry of a diamond change the way light passes through a diamond. As a result, a well-proportioned diamond reflects most light back internally. Light passes back to the eye through the table facet.
Modern round brilliant-cut diamonds feature 57 facets. They’re modern proportions guarantee brilliance in very good and excellent cut grades. But, historically, older cut diamonds featured deeper proportions and 58 facets with a culet. This allowed light to pass through the bottom of the diamond. As a result, reduced proportions resulted in less brilliance.
The result we refer to as brilliance. Conversely, a poorly proportioned diamond leaks light. As a result, poorly cut diamonds appear far less brilliant by comparison. Diamonds sparkle owing to the effect of brilliance with additional factors.
What is diamond fire?
Light passing through a diamond bends. As visible light passes through a diamond, it splits into different colours. We see the same effect in water droplets when a rainbow forms. This same effect occurs when light passes through a prism resulting in a rainbow of coloured light. In diamonds, this effect appears as random bursts of colour—most noticeable in bright sunlight.
This means that a beam of white light going into a diamond comes out as a spectrum of different colours. When we see the colours of the spectrum in a diamond, we call this fire.
Some diamond cuts exhibit greater fire than others. For example, Emerald-cut diamonds give greater fire but less brilliance. In contrast, brilliant-cut diamonds demonstrate greater brilliance and less fire.
A diamond splits white light into colours of the spectrum, referred to as ‘fire.’
What is scintillation?
The effect of light and movement creates scintillation. Scintillation is the play of white and coloured flashes of light seen when the diamond is viewed in motion. Viewable with the naked eye, scintillation is the life of the diamond.
We divide scintillation into flash scintillation and fire scintillation. Flash scintillation comes from bright flashes of light dancing across the polished facets of a diamond. When this effect throws flashes of colour, we refer to this as fire scintillation.
The quality of a diamond’s polish results adds or subtracts from the scintillation. An excellent polish assists in the reflection of light from each facet of the diamond.
The effect of fire, brilliance and scintillation on a diamond
The combined effect of fire, brilliance and scintillation gives a diamond life.
Together, the beauty of a diamond comes from the “across-the-room-sparkle.”
Few gemstones have this overall effect. We should remember that without light, diamonds have no brilliance, fire or scintillation. Light brings a diamond to life with an effect that few gemstones achieve.
How to keep the sparkle of your diamond
The attraction of grease and dirt to a diamond causes the loss of diamond sparkle. The build-up of hand creams and oils on the back of a diamond ring causes significant loss of sparkle. Remember to clean your diamond regularly using the Dazzlestik to restore sparkle.
About Mark Johnson
My name is Mark and I'm founder at Serendipity Diamonds. By day you'll find me working in our showroom—in a variety of roles. My work (which I love) ranges from photographing jewellery, to writing blog posts and helping clients with my colleagues Drina, Emily and Debbie.
