Diamonds are weighed by the carat. 1 carat = 200 milligrams = 0.2 grams. 1 carat can be divided into 100 cents, which are also known as points. 0.75 Carat is equal to 75 cents, 0.01 Carat is 1 cent. Holding other factors constant, the value of a diamond increases as its weight increases. Diamonds of equal weight will differ in value according to differences in their colour, clarity and cut. Diamonds of good quality come in all sizes and shapes, therefore the most important thing is to find one of your ideal size and style.
Every diamond contains natural inclusions, for instance naturally occurring blemishes. The quantity, size, shape and colour of these inclusions determine the clarity and uniqueness of a diamond. Inclusions are imbedded inside a diamond, and can be white, black, opaque or even green or red in colour. Most inclusions cannot be seen by the unaided eye, and can only be observed by 10-power (10X) magnification by a skilled grader.
Clarity is the system that measures the quantity of inclusions and blemishes in a diamond, ranging from Flawless/Internally Flawless to Included. Blemishes in diamonds of the Included grade can be observed by the unaided eye. Flawless/Internally Flawless Diamonds:
Flawless/Internally Flawless Diamonds:
- Flawless: Under 10-power (10X) magnification, no inclusions or blemishes are observed.
- Internally Flawless: Under 10-power (10X) magnification, no inclusions are observed, only small blemishes.
Very Very Slightly Included (VVS1 and VVS2) Diamonds:
- VVS1: Diamond has very very small inclusions, which are extremely difficult to observe under 10-power (10X) magnification.
- VVS2: Diamond has very very small inclusions, which are very difficult to observe under 10-power (10X) magnification.
Very Slightnly Included (VS1 and VS2) Diamonds:
- VS1: Diamond has very small inclusions, which are difficult to observe under 10-power (10X) magnification.
- VS2: Diamond has very small inclusions, which are relatively easier to observe under 10-power (10X) magnification.
Slightly Included (SI1 and SI2) Diamonds:
- Diamonds have obvious inclusions which, under 10-power (10X) magnification, can be easily observed (SI1) or very easily observed (SI2).
Diamond colours fall into two categories. Colourless diamonds can be clear, or have a hint of faint yellow or light brown; while coloured diamonds are commonly yellow, grey, pink, etc. Colourless diamonds are usually graded according to the Gemological Institute of America’s (GIA) D-to-Z Scale, which ranges from from D (colourless and clear, starting from the first letter of “diamond”) to Z (yellow). Coloured diamonds are extremely rare and vibrant in saturation, ranging from pink, blue, green, yellow to a very rare red. GIA’s D-to-Z Scale is not applicable to coloured diamonds.
Cut refers to the proportions of the diamond, which are determined by the skill of the craftsman when cutting the stone. According to the rules of geometry, a perfectly cut diamond should reflect light internally in such a way that all light is concentrated on the crown of the stone, which gives it brightness and flashes of colour. In an over-finished or under-finished stone, light leaves through the pavilion, leaving the diamond dark and unattractive. Therefore, the better the cut, the higher the value of the diamond.
- Ideal Cut: Only 3% of top diamonds are in this grade. Almost all light that enters the diamond is reflected, representing an elegant and outstanding cut.
- Very Good Cut: About 15% of diamonds fall into this grade. The diamond is of very good cut and can reflect a good amount of light, but is of a slightly lower price range.
- Good Cut: About 25% of diamonds fall into this grade. The diamond reflects most light that enters.
- Fair Cut: Roughly 35% of diamonds fall into this grade. The diamond is still of good quality, but the cut is average and the amount of light reflected falls short of the Good grade.
- Poor Cut: Diamonds of this grade do not reach average industry standards. The diamond is cut either too narrow or too wide, thus it loses light through the sides or the bottom.