What is Diamond Scintillation: A Key Diamond Attribute

Diamonds are the top gemstones in the world and their value is based on an array of factors. Much of the value of the stone rests on its carat or size, and durability combined with its visual character. The latter is determined by the stone’s interactions with light. A key visual feature of diamonds is their scintillation. Which is one of a number of important light-related effects the gemstone produces.

Among the most notable is diamond scintillation. Call it the dance of light in motion. Diamond scintillation is one of the most interesting and captivating features found in the famous carbon-based gemstone. Which is the subject of study on this Education page.

The Basics of Diamond Scintillation or Sparkle

The first point to consider is that diamond scintillation or sparkle as it is sometimes known is a natural attribute of diamonds in their cut and faceted state. This is to say that uncut or rough diamonds do not showcase this attribute.

This means that the quality of a diamond’s scintillation greatly rests on one of the 4Cs: the cut of the diamond in relation to the other Cs which have a lesser effect. For those who are new to the subject of diamond scintillation, is best to familiarise themselves with the 4Cs of diamonds. Notably, diamond clarity as this point builds on that.

Since we have now established that diamond scintillation is a product of the diamond’s cut and faceting, the next step is to understand what exactly the term scintillation refers to. We have already hinted at the answer to this question: that is a pattern of light that flashes from the various facets of the stone.

To think of a visual example, if you have been to a gem cutter, or diamond jewellery store, or watched a video of real diamonds, the scintillation is the effect that you see as the diamond is slowly turned: as the gemstone moves the various facets on the stone start to scintillate with various levels of light: some bright, some dark. But they glow, almost like taking turns.

But what does that mean exactly in relation to the physical structure of the carbon-based stone? To answer this question it is important that we distinguish the aspect of scintillation from two other notable diamond quality factors that are a product of its faceting.

What Diamond Scintillation Is Not

When it comes to understanding the visual quality of diamonds two other factors make up the visual character of the cut stone. They are its brilliance and fire. These terms are popular in describing the quality of the gemstone cut (one of the 4Cs), but at times they are confused with scintillation.

The brilliance of the diamond refers to the overall brightness of the stone. The central factor of a diamond’s visual quality, the brilliance of the stone is based on the level of white or colourless (but bright) light that the diamond shines with.

Now there is likely to be some confusion between brilliance and scintillation since they both deal with the interactions of light on the gemstone, and are a function of the cut and faceting the stone has been subjected to. However, they differ in that the scintillation is primarily a product of the internal effects of light, upon hitting the stone, and how that produces the unique flashes of the stone. The brilliance on the other hand is a result of the refraction of light from the surface of the stone.

The fire of the diamond, also known as dispersion refers to the break up of white light in the spectrum of rainbow-like colours as it hits the stone, and becomes most visible on the diamond’s crown. Now some in the industry have sought to separate out the interior lighting effects of diamonds in relation to the breakage of light into subcategories of fire scintillation and flash scintillation. However such classification is not widely accepted and tends to blur the lines between fire and scintillation. What the reader needs to know is that scintillation does not deal with coloured lights as those found in a prism.

Requirements for High Scintillation

As noted the diamond’s faceting plays a central role in the stone’s scintillation. And along with it the other two visual factors were mentioned above. When it comes to producing a gemstone that showcases a high level of scintillation, this outcome would depend on the quality of the cut. Which in turn is built on the symmetry, alignment of the facets and the overall shape of the stone.

As a simple rule, when you are looking for a diamond that showcases high scintillation it is advisable to seek a diamond with a high diamond cut grad. In the diamond industry diamond cut is graded from: Excellent, Very Good, Good, Fair to Poor. Any diamond that lies above the Good cut range will be a solid choice when it comes to scoring highly in diamond scintillation.

When it comes to diamonds that are able to showcase solid scintillation a key requirement is that the faceting of the stone is mapped in a particular way to optimize larger reflections. This is a technical point that comes down to the quality and thus the skill of the diamond cutter and faceting tools that are used. The quality of these features in a single-cut diamond will rest on its symmetry. The precision with which the gemstone is shaped will help maximise the scintillation and also the stone’s fire and brilliance.

The Relationship between the Quality of the Cut and Diamond Scintillation

When speaking of the quality of the diamond cut it is easy to get carried by the grading of the specific gemstone: In terms of it being cut as Excellent, Very Good etc. However, underlying these are the proportions of the cut stone.

This is a key consideration when going for top quality diamonds that can showcase high scintillation, as a diamond with poor proportions, as such those found in shallow, deep cut stones, then the visual effect will be greatly lessened. As in these, non-ideal cuts (as ideal cuts are the best), light that hits the stone will ‘leak out’ of the sides, making the stone look less glowy, at the same time affecting the scintillation of the stone.

Holding all of this together is the specific shape of the cut diamond. It is important to note that certain diamond cuts (or shapes) are better at showcasing lighting effects like scintillation. Among the most notable is the round brilliant cut. However other cuts, with higher clarity and cut grades can also score for this key diamond attribute.