With the Cricket World Cup in full swing, we thought it’s time for a cricket related post, and what better subject than diamond grading?
Diamond grading refers to assessing the 4Cs of a particular diamond – the carat weight, colour, clarity and cut. These four factors can be classed being either objective, subjective, or, a bit of both.
Now assessing carat weight is simple – put it on a scale and read what it says, and perhaps round that number off to two decimal places. This number is pretty much indisputable, a lot like if a bowler clean bowls a batsmen.
When it comes to grading colour and clarity, these are mostly subjective.
Clarity is assessed under a microscope with a 10x lens. If a grader gives a higher grade to either colour or clarity, it is called a “soft grade”, a lot like if a cricket umpire gives a batsmen out LBW when the ball was clearly going down the leg side. However, if there is a clearly visible (at 10X) cloud in the middle of the table, it would likely be graded either an SI1 or SI2 by any lab, much like a plum LBW would be given out by any umpire.
Colour is assessed using master stones. Sets of stones are usually difficult to acquire, as they may well need to be collected over time. The payoff for this is that they provide the most accurate way of assessing colour. Recently, companies like Sarin have developed a Colormeter – an electronic device used to assess colour. This, like some technological developments in cricket has met with a lot of controversy as some like it, some don’t agree with the scientific methods behind it, and some are just techno-phobes.
The last C is cut. Cut essentially refers to how much light is returned by the diamond. Most major labs assess cut through a diamond’s proportions and assign a grade according to those proportions. This, funnily enough, is a lot like an umpire deciding whether or not to stop play due to bad light – that is, they will measure the level of light and make a decision based on that.
Lastly, as with any type of umpiring, the umpires will, over time develop good or bad reputations, and there will always be an armchair expert to criticise or disagree with a lab’s grading (this is usually done for their own gain).