Knowing About the School of Diamonds

Knowing About the School of Diamonds

So you have decided to purchase a diamond. Regardless of the occasion – a proposal, an anniversary, or just because you want one – buying a diamond is not a decision to be taken lightly. Rather, it should be researched on and carefully considered. Knowing about the School of Diamonds is important, so says Mr. Isaac Poh, Diamond Specialist and Founder of local diamonds jeweller, Vivo Diamonds.

We ask Mr. Poh some questions.

1. We all know there are 4 C’s in choosing a diamond ring. What does each of them mean, and how do they affect a diamond’s appearance and price?


While many diamonds appear colorless or white, they may actually have subtle yellow or brown tones that can be detected when comparing them side to side. The color grades start at D and go down the alphabet. Truly colorless stones, graded D, are extremely rare and very valuable. D, E and F are often called collection colors. The subtle variances are so minute it is difficult to identify them in smaller sizes.

Since being colorless is most sought after, D, E and F diamonds have a greater value, all other factors being equal.


A diamond’s clarity is a description of its internal purity. With fewer imperfections in the stone, it is rarer and has a higher value. This measure of imperfections or blemishes in a diamond is critical, and will result in price differences, all other factors being equal.


A carat is a weight measuring unit equal to 0.2 grams. The larger, whiter and cleaner the diamond, the more rare it is. Accordingly, the cost per carat of a large diamond will be higher than that of a smaller diamond of the same color, clarity and cut.

More weight equals more money, so diamond cutters may sacrifice brilliance to maximize carat weight and profit. It is vital to realize that weight does not always equal size or beauty. So experienced cutters may sacrifice weight and focus on cut to get the most beautiful and brilliant Hearts and Arrows diamonds on the market today.

Diamonds are valued on a per-carat basis. For example, a diamond of exceptional quality may sell for $20,000 per carat, while one of a lesser quality may sell for $1,000 per carat; so a three-carat stone could be $60,000 or $3,000. Diamond values also increase disproportionately as stone size increases. So if you take a stone of a particular cut, clarity and color, and move its carat weight to the next price category, you might see quite a hefty price differential.


A diamond’s cut is not only about its shape, but also about how effectively it can return light to the viewer’s eye. A well-cut diamond will appear very brilliant and fiery while poorly cut stones can appear dark and lifeless. Well-cut diamonds also appear larger than other stones of the same carat weight.

An ideal cut generally garners a 20% to 30% higher price than one that is just “good”. The diamond’s shape can also affect its value, though usually to a lesser degree than its cut does. Generally, because of the popularity and demand for larger round diamonds, they cost more than fancy-shaped diamonds of comparable size and quality.

2. Tell us about the different diamond shapes. Which are the most popular ones, or the rarest, or the most expensive?

The most important factor in determining shape is to choose which appeals to you most, and what looks best on your hand. If you are the more traditional person, go for the classic round brilliant diamond; if you tend to be more unconventional, you might prefer the pear, marquise or heart shapes. Longer and shorter stones can also visually affect the appearance of your hands, making them look longer or shorter respectively.

Round brilliant-cut stones show the most brilliance and sparkle. Its design allows it to hide flaws and yellow tints better than the other shapes. Emerald cuts, which have long and flat facets, emphasize flaws the most and are not as brilliant.

If you want your diamond to look as big as possible, consider a fancy shape like the oval or the pear, which appear larger than round diamonds of the same carat weight.

The rarest diamond cut is the ‘ideal cut’. It reflects nearly all light that enters the diamond and creates the maximum fire and brilliance.

As far as price goes, heart- and marquise-shaped diamonds tend to be the most expensive shapes because they waste a good deal of the crystal’s rough form.

3. Which is the most important ‘C’ in the art of choosing diamonds?

This is in part a matter of taste. If size is key, then carat weight will count most to you – but remember that size is not related to the beauty of the stone. A smaller diamond that is more masterfully cut and features greater clarity and better color will be more beautiful and brilliant than a larger stone of the same price, but which does not meet the same standards where the other three ‘C’s are concerned.

Cut is arguably the most important factor because when a diamond is cut to ideal proportions and with precise symmetry, light is refracted from one facet to another and then dispersed through the top of the diamond, giving it maximum brilliance. The expert diamond craftsman always attempts to cut a diamond in a way that makes the best use of light.

Here is the bottom line: brilliance is the wow factor in any diamond. It’s the arch in a person’s eyebrows and the squint in the eyes when he or she is nearly blinded by the magnificence of the diamond. For a diamond to be exceptionally beautiful, all the 4 ‘C’s must be present. But without the cutting skill of a master artisan, a rough stone will never release its optimal brilliance and beauty regardless of how good its color, clarity and carat are. So, pay extra attention to cut.