To the consumer, it seems that a great deal of mystery normally shrouds the business of shopping for diamonds. And yet, there are simple factors that combine to determine the quality and value of each individual stone. For those in the trade, there is no mystery.

Certificated diamonds are a commodity whose worth is precisely quantified and itemised according to agreed standards. This section of The Diamond Shop is intended to help you understand more about the facts underlying the lore of diamonds, and what exactly the characteristics are that determine the value of individual stones.

When you know what the terms that are used in the trade actually mean, you'll feel more confident that you can judge whether you are receiving value for money. You'll be able to compare like with like when checking prices with different dealers.

The important thing is to learn "the four C's"; these are:

• Carat
• Clarity
• Colour
• Cut

These four attributes determine the value of the diamond you are buying. They control what the dealer pays, and therefore what you pay.

Learning the 4 C's will allow you to make comparisons and shop wisely.

Don't worry, though. As long as the stone has a certificate from a recognised laboratory, such as GIA, those differences will be set out in black and white.

GIA are even laser-etching microscopically small identification marks onto the girdles of their authenticated stones so that you can be assured that the diamond and the certificate do indeed match.

So, let's get started... First of all, let's consider the most familiar attribute, the weight of the diamond, which is measured in Carats.

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