Diamond Clarity

Diamond clarity measures the presence and severity of the internal marks, blemishes and flaws found in almost all diamonds. Whether natural or lab grown, it is incredibly rare to find a diamond totally free of such inclusions, but they do exist, and are known as ‘flawless diamonds’. The closer to flawless, the higher the diamond clarity, the rarer it is and greater the cost.

Mined diamonds form deep within the earth over billions of years. Intense heat and pressure in the mantle encourage carbon molecules to crystallise and grow, picking up and trapping traces of other elements as they form. Small cracks and flaws within the diamond can form, also referred to as inclusions or blemishes if on the surface of the stone. The severity of these marks are measured on a diamond clarity scale.

The small marks and flaws found within diamonds are given the umbrella term ‘inclusions’, but there are many different types of diamond inclusions, caused by different phenomena. Some are more notable than others:

• Crystal - a minuscule diamond (or other mineral) within the diamond; sometimes coloured
• Pinpoints - tiny white or black crystals, appearing like a pinprick within the diamond
• Needle - an elongated, thin line of crystal
• Cavity or chip - usually caused by stressing a weak point during diamond cutting, a cavity in the surface
• Feathers - an internal crack or fissure, appears light and feather-like, sometimes transparent without magnification
• Clouds - a cluster of pinpoint inclusions, which can make a diamond appear milky or hazy
• Knot - a small crystal that breaches the surface of the diamond, like a tiny bump on the surface
• Graining - like you might find in wood, long streaks or lines that can look like scratches within the diamond, usually more visible from certain angles of the diamond
• Twinning wisp - these show the moment a diamond stopped then restarted growing; often two amalgamations of pinpoints, needles, feathers and cloud inclusions that point to separate phases of growth

Clarity is graded on a scale from FL (flawless) to I3 (heavily included), with VS2 to SI1 typically offering the best value – eye-clean to the naked eye, without the premium pricing of higher grades. Flawless diamonds are the rarest and most expensive, but inclusions in the VS2 to SI1 range are usually only visible under 10x magnification.

When clarity is assessed, a number of factors are considered: how visible the inclusions are under magnification, where they’re located within the diamond, their size, colour and how many there are. Each is carefully recorded and mapped out to assign an accurate clarity grade.

For natural diamonds, clarity has a more noticeable impact on price, so VS2 to SI1 tends to offer the best balance of beauty and budget. For lab grown diamonds, we generally recommend VVS1 to VS1, as high clarity grades are more readily available at accessible prices – thanks to the controlled environment in which they’re grown. In most cases, there’s no need to compromise on clarity when choosing a lab diamond.

That said, the ‘best’ clarity depends on your priorities – whether that’s microscopic perfection or a great-looking diamond at a smart price. Either way, Queensmith can help you find the right fit.

To a degree, inclusions don’t affect a diamond’s sparkle – from ‘Flawless’ down to ‘Slightly Included 1’ (SI1), the internal marks are typically too minor to interfere with light performance. However, diamonds graded lower than SI1 can have inclusions that start to impact brilliance. Heavier inclusions disrupt the way light travels through the stone, reducing the amount that reflects back to your eye. In short, it’s only diamonds graded ‘Slightly Included 2’ (SI2) and below where inclusions may noticeably diminish sparkle.

See the diagram below to compare how light behaves in a minimally included diamond versus a heavily included one.

Clarity is the ideal characteristic to compromise on when purchasing a diamond as inclusions are blemishes that are typically invisible to the majority of viewers. Reduce the cost of your diamond by looking between VS2 to SI1 grades, which won’t be flawless but will appear clear to the naked eye. You should only be able to see inclusions in VS2 to SI1 diamonds with a microscope.

If you look lower than SI1, you’ll start to spot inclusions without the aid of magnification, and heavy inclusions can even reduce the brilliance of the stone as the marks interfere with light return. Without a microscope or loupe, you probably wouldn’t be able to tell the difference between a FL diamond right down to SI1.