How to choose a diamond
Choosing a diamond, like any other gemstone, should be a personal decision. There are certainly factors that affect price, like the well-known 4 Cs, but if the purpose of buying a diamond is to give joy, either to oneself or a loved one, it’s essential the buyer chooses a stone they love.
Here’s our guide on the 4 Cs, how they affect the value of the stone, and useful links to help a buyer decide what they like.
Diamond Carat Weight
A common misconception is that a diamond carat refers to its size. Diamond carat is actually how much a diamond weighs with a metric “carat” is defined as 200 milligrams. Each carat can be subdivided into 100 ‘points.’ This allows very precise measurements to the hundredth decimal place.
Does size matter?
Not necessarily, as a diamond’s cut will determine how it looks. A poor cut will make a high-carat diamond look small and deep. A better cut will maximise a smaller carat.
The cut of the diamond is the most important factor of the 4C’s. A poor cut, can make your expensive diamond appear dull and lifeless; a cut too deep and it makes your diamond appear smaller. An experienced cutter will be able to create sparkle, increase the appearance of clarity and colour grade.
The GIA Cut Grading System for the standard round brilliant diamond evaluates seven components: brightness, fire, and scintillation, weight ratio, durability, polish, and symmetry, assess a diamond’s design and craftsmanship. The first three consider the diamond’s overall face-up appearance, whereas the last four assess a diamond’s design and craftsmanship. The first three are the most important factors as this is what people can “see” of the diamond.
Internal and external white light reflected from a diamond.
The scattering of white light into all the colors of the rainbow.
The sparkle a diamond produces, and the pattern of light and dark areas caused by reflections within the diamond.
The most common shapes in diamond cutting
Diamond clarity refers to the grading system of both surface and internal imperfections. Surface flaws are called blemishes whilst internal flaws are called inclusions. Blemishes and inclusions are microscopic with most being unable to be seen by a untrained or unaided eye, and do not affect the diamond’s beauty. After cut, carat and colour, clarity is the least important of the 4C’s when buying a diamond.
Assessing the diamond clarity looks at the number of inclusions and how their position or size may affect the overall appearance of the diamond. The value in clarity is the less inclusions, the higher the value.
The GIA Clarity Scale has 6 categories, some of which are divided for a total of 11 specific grades.To the naked eye, a VS1 and an SI2 diamond may look exactly the same, but these diamonds differ in overall quality and value.
- FL & IF Diamonds (Rare Finds)
Slightly Included Diamonds
- VVS Diamonds (Excellent Quality)
- VS & SI Diamonds (Best Value & Most Popular)
Diamond colour is the second most important factor to consider when buying a diamond. The rating scale goes from colourless to light yellow or brown (this does not include canary diamonds). The higher the quality, the closer to colourless the diamond becomes.
GIA’s D-to-Z color-grading scale is the most widely accepted colour grading system. Beginning with the letter D, representing colorless, and continues, with increasing colour, to the letter Z with these distinctions make a very big difference in diamond quality and price.. This is completed by comparing a stone to masterstones under controlled lighting, GIA assesses the colour.
To the untrained eye, many of the colour distinctions are so subtle that it may be impossible to compare without the assistance of a trained jeweler.