How To Spot A Good Diamond
Dirk says first and foremost, look for a stone that is 'alive', has sparkle and lustre. Can you see a black inclusion, or imperfection? Is the stone flat, is the clarity not good and colour down?
If you answer yes to any of these questions, then do not buy a stone. Ultimately, there are four factors that determine the value of a diamond, known collectively as the four Cs.
The Four C's
Impurities in a stone block light. Although these inclusions as they are called, make a stone unique, the fewer there are, the more valuable the stone is. The standard measurement starts from flawless (IF or IF) to imperfect (I). To be flawless, a stone must have no inclusion visible to a trained eye, even under 10 times magnification under a good light.
Diamonds can come in every colour of the spectrum but the most popular are colourless. Icy white diamonds are extremely rare and therefore the most expensive. Stones are graded by how far they stick to or deviate from the purest white, starting from the grade of D, descending down through the alphabet. Every letter designates a more yellow tint.
This is the weight of a diamond. The word is derived from the carob seeds that were used to balance scales in the past. A carat is equal to 200 milligrams and there are 142 carats to one ounce. There are about 100 points to one carat. A common weight sold is one and a half carats.
A poorly cut diamond will lose light and appear dull which is why this is such an important element. The most popular cut, the round brilliant has 58 small,