Carat means the unit of weight for diamonds and the most important aspect to evaluate. Each of the carat is divided by 100 and one carat weight is equivalent to 0.2 grams. The cost of a diamond is directly related to the carat weight. This means you have to pay more for buying more carats. For example, if you buy two carat diamond then it will cost you almost double the price of one carat diamond. So, you should always know the carat of the diamond you wish to buy.
Cut is another important aspect as better the cut more the brightness. A better cut diamond reflects more light increasing its worth. Cut is also important to get the right shape for the diamond. Be it round, square or any other shape, a perfectly cut diamonds grabs more attention than a poorly cut diamond. Also, people generally tend to buy diamonds that have stylish shapes and are shiny. So, the prices of well cut diamonds are set higher.
Diamonds are graded from D to Z according to their colours. Generally diamonds with A grade to D are colourless and the most expensive ones. Only an expert can tell the grade of your diamond from its colour. It is not possible for a layman to distinguish between the minute colour grades. They may all appear the same.
Clarity means the number of flaws the diamond has. When the flaw is internal it is called inclusions and when the flaw is external it is called blemishes. A flawless diamond is very rare. So, when you are buying a diamond for the first time don't get carried away by the claims of the marketing person. Check for the clarity yourself as lesser the clarity higher is the price.
Certification or certs can be called as the 5th C but carries a lot of weight. If you buy diamonds that are not certified then you may end up buying diamonds which are not accurate and has been enhanced. Diamonds are enhanced artificially to make them look good and flawless. Therefore, you should always buy diamonds that are certified by reputed agencies like Gemmological Institute of India (GII) and ensure that you buy the rightly priced diamond.
Diamonds are good investment options but you must be very cautious while buying them. You must check the accuracy properly otherwise you might end up losing money.