The Notorious 4 C’s

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…and how to not be so obsessed

If you have started your engagement ring research you probably have stumbled upon the 4 C’s: Cut, Clarity, Colour and Carat. The four C’s are used as a system for grading and attributing value to diamonds. Interestingly however, it is a system ONLY used for diamonds. Of the 200-ish different types of gemstones, diamonds are the only stones where the four C’s are used. Consequently, value for the other 199-ish type of stones is driven by the market and fluctuates wildly from seller to seller, and market to market. So yes, we need to be tuned into the four C’s when picking diamonds, but just keep in mind, there are literally hundreds of other types of stones that don’t slavishly follow the four C’s. But back to diamonds…

What follows is a quick and dirty version of the four C’s. For a much more indepth overview read the GIA’s version.

  1. Cut – More than just its overall shape viewed from the top (i.e set in a ring). It is a sneaky multi-factor assessment of the shape (i.e. round, oval, pear etc) and also the type of cut (i.e., step, brilliant, rose etc). It also refers to the proportions of the table (i.e. ENTER HERE) girdle (i.e. ENTER HERE) and pavilion (i.e. ENTER HERE) and how they can be optimized for maximum sparkliness.
  2. Colour – An alphabetical colour scale starting at D (I know…what about A-C), were D is colourless and Z is pale yellow
  3. Carat – How much the diamond weighs. It has nothing to do with its shape, or size of the diamond when viewed from the top. For example, two 1ct diamonds can look very different when set in ring. Some diamonds can be cut to 1ct, but have a very small table (i.e. the top), therefore they will look smaller when set in a ring to a diamond cut with a large table.
  4. Clarity – Refers to how included (i.e. how much stuff is in the diamond that isn’t clear) the Diamond may be. It is measured on a scale from Flawless to Included. Inclusions can be fractures, little bits of carbon, crystals feathers, graining etc. All these variations effect the  brilliance (i.e the sparkle) of the stone but only slightly. Think of them like little birth marks, blemishes or freckles. All gemstones have inclusions; some just smaller than others or some that have been cut away in the faceting (cutting) process. A flawless diamond is just a flawless part of a larger diamond hacked off. Not that fancy is it?


Image Courtesy of GIA

Ok now you sort of know a bit, here is the most common mistake I see with each C

Number one rule: just chill—don’t get so involved in the nitty gritty of the four C’s. Unless you are armed with a scale, a loupe and a gemmology qualification, you probably won’t notice most of the differences. The difference in each point of the scale is very minimal to the end consumer but, those tiny changes will cost, or save you a lot of money depending which side of the scale you fall on.

Remember that although the 4 C’s are used to help value and differentiate diamonds, they are also very much a marketing tool designed to make you want the best and pay for it even when it’s only slightly better than the “worst”. It’s a beautiful clash of behavioural economics and the law of diminishing returns at its finest. I would argue, you as consumer can’t tell the difference between a [1ct, F, D, Triple Excellent Cut and a 1ct H, Si2, Average Cut], so why pay the extra few hundred dollars?


The shape of the stone is just a personal preference, but because round brilliants are the most demanded shape they are more expensive. PRO TIP get more bang for your buck and go with a marquise shape or another fancy shape (literally the technical term) instead of a round brilliant, it’s more fun anyway. They are called fancy shaped for a reason. Who doesn’t want to be fancy?

The relationship between the proportions of the crown (top of the gemstone – you wear a crown on the top of your head), the girdle (the bit in between the top and the bottom, no fancy remembering thing here) and the pavilion (the bit that looks like an upside circus tent, or the triangle pointy bit – whatever helps you remember) effect the brilliance of the stone, aka how sparkly that sucker is or how much light is refracted back to you when you look at it. It’s a bit of complicated physics about light refraction etc. The beyond Four C’s blog goes into painstaking detail about it if you’re keen. But, if you want to know my opinion on the matter:  you can opt for a triple excellent cut, but honestly, you won’t be able to tell the difference between that and something that is an excellent cut or even just average. So again, why pay for something you can’t even see?.

This is what I mean about obsessed. Don’t get so caught up in four C measurements. Below I’ve linked an interesting and informative video which shows how carried away you can get with cut. I am a gemmologist and I couldn’t work out which stone was ‘better’ until the video told me. There is a lot to be said for personal preference too. Check out the video here – Can You Tell Which Is The better diamond? Both of the same GIA Certificate Grades

Don’t waste money on triple excellent cuts unless this is super important to you. As a lay consumer you won’t be able to tell the difference between an average cut and a triple excellent cut. And even if you could pick it when in the actual f*&% are you going to be staring so close at two stones and comparing them when the stone is in a ring on your loved ones finger?


When you see colour scales your immediate reaction is eww, I don’t want any of those yellow tinged gross diamonds. I think I should probably get a D colour, like maybe an E or an F, but eww. Honestly, if you saw any colour diamond from a D to an M by itself it would look white. I would only be cautious if you’re setting the stone in yellow gold as this would enhance the yellow in a K to M. So if yellow gold is your thing, maybe go whiter than otherwise. But if you’re setting it in white gold or platinum, it will actually help wash out the yellow tones. So there is a few hundred dollars saved there.


Remember, you are only picking one stone. So assess colour on its own, not next to another stone on the scale. PRO TIP (if this becomes a trend I am claiming I forecasted it here first). Colours S through to Z have a noticeable yellow tint which is a really lovely pale pastel lemon colour, I actually think they should be called lemon diamonds and think they would look spectacular in yellow gold. They are generally a lot cheaper than whiter diamonds. Who wants a canary yellow diamond anyway. I’m telling you lemon diamonds are where it’s at! I think their price is about to sky rocket much the same way brown diamonds have now been remarketed as chocolate, champagne and congac diamonds LOL! They used to be worth nothing and now they be expensive AF.


Carat refers to the weight of a diamond. What you notice when you look at the shape of a diamond is that most of the size of the diamond is actually in the pavilion (i.e. the bit that looks like an upside circus tent, or the traingly pointy bit at the bottom). This is to optimise the angles so light is refracted back to you and increases the stones brilliance. So once set in a ring the thing you actually see is the crown and hence this is the bit that will translate to how big it actually looks. Two diamonds both equalling 1ct can have different crown dimensions. Optimise this shit, although the difference may only be 1/2 a mm or so, this actually can make a big visual difference on the finger. It is probably a significant percentage of the dimension of the stone.

Also, shop for random carat weights like .79cts, .89cts, 1.29 etc, and check out their dimensions rather than searching directly for a 1ct or 2ct like the other silly people who haven’t read this blog. If you graph price against carat you’ll see a jump to the more rounded weights, i.e. .5ct, 1ct, 1.25ct. A 1.23ct diamond is worth way less than a 1.25ct diamond, but is only slightly smaller. So, shop random sizes with bigger crowns.

Also, think about carat in relation to shape. A 1ct round cut has a crown of usually around 6mm; but a 1ct oval is usually around 6x8mm. An oval is not only bigger, but will most likely be cheaper because of lower demand. There are economic benefits to not being boring. One thing to remember is to not get too carried away with the dimensions as this can start to effect cut, it’s a dance people. Too much of a party up top in the crown can affect the critical angles and can make for a dull boy diamond. Take a little here, give a little there.


Look at the stone dimensions and find that balance between the dimensions, carat weight and cut proportions. Look for random weight values and check out the fancy shapes to get more bang for your buck.



Clarity is probably the biggest marketing scam of them all. FACT: inclusions will affect the brilliance of a stone, because inclusions will disrupt the light path or break it up. Instead of bouncing (refracting) the light back to the viewer, the inclusion will offshoot it in another direction. This causes light leakage and reduces brilliance, fire and scintillation (i.e. sparkiliness, the rainbow colours and pop).

A flawless stone isn’t flawless. It just means that under 10x magnification you can’t see any inclusions. I don’t know about you, but I ain’t walking round the streets inspecting people’s rings with magnifying glass. I’m just using my boring old eyes.

With Clarity it is safe to stick with VS2 or better. If you don’t mind a bit of a dark spot here or there (I would say 80% of my clients couldn’t pick out the inclusions unless I pointed them out) go with a Si1 or Si2 diamonds. You can save yourself some goooood moolah here. PRO TIP: when you are shopping online, pretty much all retailers magnify the diamond by 10x or more to highlight the inclusions and push you to spend more money by wanting one with less inclusions. They are dummy diamonds designed to push you towards the one with the bigger price tag. Basic human psychology peeps. Don’t be fooled by this simple marketing trick. Remember we don’t view diamonds with a magnifying glass. We look at them with our boring old eyes. So, make sure you are looking at images that are actual size (it’s usually another option when viewing at gallery images of diamonds).


Don’t shop under magnification. Most people can’t see inclusions with the naked eye until pointed out. Shop in the Si1 and Si2 range to get bang for your buck.

There is so much marketing and consumer behaviour analysis that goes into selling you diamonds. Why? Because there is a lot of money to be made. Those big sites, you know the ones that stalk you across the internet shoving ads in your face the second you innocently Google engagement ring, gamify their shopping experience by introducing multiple sliders and filters and men in particular fall for this hook line and sinker. It becomes a game, a challenge, to find the best diamond. But the house always wins. They set the rules on their sites. In the end you are more likely to be scammed, fooled and ripped off.

At the end of the day you will find the diamond or gemstone that speaks to you on an emotional level and all these silly analytics will go out the window. Whatever stone you pick I believe the stone chooses you anyway.

Do your research! Be clear about what is important to you, but don’t get obsessed.  Remember we look at diamonds with our eyes. We don’t sit and compare diamonds once they are set in rings on fingers, and most people can’t tell the difference between a white sapphire, diamond or  moissanite  anyway. So why would we waste our time getting so obsessed with the silly four C’s?

As a gemmologist I take a gemstone focused approach to this whole process. I ensure I spend time educating my clients without marketing hooha, sales pitches and gamification. I am passionate about working bespoke to a client’s needs so that we can find the best diamond or gemsonte within their budget. We gladly work within any budget.

Book a consultation to see how I can help you create your dream engaged ring designed to get a “Yes!!” — plus its free and I’m super friendly.


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