Why is it important that my diamond certificate come from an independent diamond grading laboratory?

If you were buying a house would you accept an inspection from the owner? Of course you wouldn’t, you would insist that the inspection be done by an expert with no financial interest in the transaction. This situation is the same when buying diamonds. Be careful of diamond reports produced in-house by diamond merchants or retailers, as the report may be inaccurate and overstate the actual grading of the diamond.

What is diamond plotting?

Diamond plotting is the process of recording a diamond’s inclusions. At the DCLA, diamond plotting is done on a computer diagram, which is then stored in a database together with all the measurements and features of a diamond. This database is similar to a finger print database, as all diamonds have unique inclusions. The diamond’s plotting is shown on the diamond certificate, and is very important in the identification of a diamond.

On the diamond certificate, or diamond grading report, it is easy to read colour, clarity, carat weight and shape… But how do I tell if the diamond is well cut?

On the diamond certificate, or diamond grading report, you must look at the proportion grade, polish grade, and symmetry grade. These three grades together determine the overall make of a diamond, and are each respectively graded as either: Excellent, Very Good, Good, Medium or Poor. The characteristics section of a Diamond Grading Report will tell you if there are any extra facets, naturals or holes in the diamond.

How do slight differences in the 4C’s affect a diamond’s value?

The nature of diamonds is such that even a very SMALL variation in any of the 4 C’s will have a significant effect on value. To give you an idea of just how sensitive the value of a diamond is to each characteristic, here are some examples (assuming all other characteristics remain constant):

Carat: a difference of 0.1 of a carat (or 0.02 grams) can affect the value of a diamond by as much as 70%.

Colour: a diamond’s colour ranges from D to Z. However the “white” colour range is from D to I (D, E, F, G, H, I). The difference between each colour is very subtle; however a D colour diamond is around 200% more valuable than an I colour diamond. The difference between a D colour diamond and an E colour diamond(which is almost impossible to tell without a set of diamond master stones) can be as much as 40%.

Clarity: even something as small as a pinpoint, which is only visible under a powerful microscope, can affect a diamond’s value. Each pinpoint could reduce the value of a diamond by 40%.

Cut: Round brilliant cut diamonds are more valuable per carat than other diamond shapes; and, obviously, well-made diamonds are worth more than a poorly made diamonds.

The value of the diamond represents between 80 and 95% of the value of a typical diamond ring. Therefore, it is easy to understand why the accuracy of the diamond grading report is so vital.

Diamond cleaning

Because your diamond when worn naturally attracts grease or oil, they will need periodic cleaning.

Even when touching a diamond with your fingers natural oils from your skin will change the brilliance of your diamond, making your diamond lose its lustre or brilliance.

A simple way to keep your diamond jewellery looking beautiful is a weekly bath in a household cleaning solution. A simple window cleaner will work. But make sure you give it a thorough rinsing followed by a very light brushing using an old tooth brush to remove the oils and cleaning liquid.

Pay special attention to the underside of the ring and bottom of the stone, as this is where most of the oils or hand creams accumulate.

Make sure when using a brush not to apply to much pressure especially if the jewellery is old or fragile. This is a good time to check the diamonds are tightly set and none are missing.

Never use Chlorine, bleaches or abrasives when cleaning diamonds set in jewellery. This will remove the rhodium plating on white gold and could leave scratches which will attract even more dirt.

If the ring has fine claws or filigree work an ultrasonic cleaner is necessary to remove deep encrusted dirt behind the diamonds. High frequency sound waves and jewellery detergent fluid will remove hard to get to dirt and grime. Make sure this is done by a professional to avoid damage or loss of stones.