Carat is a measure of the purity of gold and platinum alloys. One carat in this sense is one twenty-fourth purity by weight. Therefore 24-carat gold is pure gold (99.99%), 12-carat gold is 50% purity, etc. In the United States and Canada, the spelling karat is usually used for the measure of purity, while carat refers to the measure of mass.
The carat system is increasingly being complemented or superseded by the millesimal fineness system in which the purity of precious metals is denoted by parts per thousand of pure metal in the alloy. The most common carats used for gold in bullion, jewellery making and goldsmithing are: 9, 10, 14, 16, 18, 20, 22 and 24 carat.
Carats are further divided into points. The price of a diamond will constantly rise proportionately to the size of the stone. The larger diamonds are very rare and have a greater value per carat. For example, when discussing points, remember that a one-carat diamond will cost much more than a 95 pointer. The word carat is taken from the perfectly matched carob seeds that were once used in ancient times to balance scales by merchants.
So, uniform and symmetrical in shape and weight are little seeds that even today's sophisticated and complicated devices cannot detect more than three one-thousandths of a difference between them.
The truth about diamonds is the size; but overall quality is the determining factor in the end. There is a balance of size and quality that makes up much of the artistic nuance of a professional gemologist or gem cutter. It is the cutter's job to produce a gorgeous lavish diamond, while giving the consumer the highest Carat Weight for their money.
Only a fifth of all rough diamonds mined are suitable for gem cutting. Rough diamonds is the raw material that a cutter works with. The cutter must follow precise set of formulas to cut each popular stone shape. A diamond shape doesn't greatly affect a stone's worth. The cutter's skill is ultimately the determining factor in maintaining and preserving the infinite beauty of a diamond. He must maintain its size and value while creating each original diamond. When the certificate is acquired, the professional evaluation will give you the diamond's exact measurement and weight, as well as the details of its other attributes, cut and quality. For exact authenticity, this analysis must always be done in an accredited laboratory.
Once you've determined what cut, color, and clarity grade you're looking for in a diamond, it's easy to determine the carat weight of diamond that will fit within your budget.
When diamonds are mined, large gems are discovered much less frequently than small ones, which makes large diamonds much more valuable. In fact, diamond prices rise exponentially with carat weight. So, a 2-carat diamond of a given quality is always worth more than two 1-carat diamonds of the same quality.
To choose the best carat weight of diamond, consider her style, the size of her finger, the size of your setting, and your budget. And of course the best carats you can find on best show of diamonds.