Diamonds: their value, quality and cost explained

A 1.2 carat round brilliant diamond where the colour (E) is premium, the clarity (SI1) less so, which makes the price more advantageous on an excellent stone.

We buy diamonds according to a client's needs, and their budget. Stone characteristics will drive value, here's how quality can effect cost.

We’ve written a few diamond guides on choosing the perfect diamond, there is always something new to learn. In jewellery though, what you know is never as good as who you know. You can be a diamond expert, but if you don't have access to good suppliers then you won't access good stones.

This blog is going to be fairly short and sweet really,  It’s a day in the life when I’m choosing diamonds for a client, on what qualities will cost them more, and those which will cost them less.

Let’s do three client scenarios, all of them were looking to buy a diamond for an engagement ring, here's what happened;

Client A – He’s got a budget of £3,000.  He’s after a bigger diamond because it's what she wants.

Client B – He’s got a budget of £5,000.  He’s all about the quality, this has to be a good looking stone.

Client C – He’s got a budget of £12,000 and he’s after a coloured diamond

So, three different expectations.  For all of these guys, let’s say it’s their first time – diamond buying anyhow!  I’ve looked at quality versus quantity in other articles, so what I’m I going to do for them?

All Three

A key conversation I have with chaps buying diamonds for engagement rings, is obviously whether they would like us to make the ring as well.  This is actually a bit of a no-brainer because if you buy the two separately, you are going to pay more than you would to get us to make the ring as well.  This is because it is two pieces of work, rather than one.  It doesn’t impact what I do to find the diamond, but it does impact how I cost it.

The other point is, that key interest to me is that we deliver a pretty stone. So whatever the compromises, it needs to look good for the investment. There will be differences, a high grade diamond will always look superior to a lower grade (as we show here). But that doesn't mean lower grade is junk.

Client A - Bigger Diamond Engagement Ring on Small Budget

For anyone, it is possible to tell the quality of a good diamond from a less good one, if you have them side by side. Now, in my general experience I don’t meet lots of people who spend their time lining up diamonds, because you have to buy them first.  Anyhow, he’s open to suggestions, but bigger is better. After our conversation, we understood that big was very important, but he was highly constrained by his budget.

I had a decent 1.2ct stone for him to view. As per the clip, you can see it looks nice (this is filmed in daylight, rather than under an led or halogen where the stone is a lot more sparkly).  It is Hsi1 but the inclusions are out of the centre of the stone, and cut is good (rather than very good or excellent).  It’s got moderate fluorescence to it, which helps keep the price low.

This will resulted in a £3,200 engagement ring with a made to order setting (i.e. existing design off the shelf, rather than bespoke hand made).  The ring looks pretty wow and so everyone is happy.  It is a pretty diamond, and it is good value. It stands up to scrutiny on its own. He had to revise his budget slightly, but for the stone size, he was willing to do so.

Things you will have to accept if you want a bigger stone for less;

• More inclusions.  This makes the clarity weaker, but with a good setting, can often be minimised.

• Colour compromise.  Forget D-F, go G-I.

• A good cut, rather than very good or excellent.

• Fluorescence - the stone can check a lot of boxes but high fluorescence drives costs down.

What you can expect from online.  

If you are buying a cheap diamond with a good sounding appraisal, expect deficiencies.  A favourite is fluorescence (see blog here), but they will be vague about inclusions and often have surface ones (look/feel like chips and are described as 'indented natural') or have stones certified by more obscure companies.

Client B - Bigger Budget for Smaller Diamond

He isn’t interested in size as much as knowing he’s got the best stone for his budget. He wants the diamond in his engagement ring to be the best in appearance it can be.

He’s not going to get an excellent 1ct stone for his engagement ring, so he wants something smaller. Stone appearance is very important here, this has got to be special.  Best value for budget is still important, but he’s looking for visible quality.

I’ve narrowed a couple of stones he will like, both deemed excellent (by GIA and more importantly, by us 😊).  The first, is a 0.70 Dvs2, again with tiny inclusions which need a lot of magnification to spot, and faint fluorescence which is just that, not something which shows up.  It is just lovely, bursting with light and colour which is what gives it a higher value.

As comparison I've got a 0.80ct Fvs2 which is just under 6mm in diameter.  It’s a lovely stone, inclusions are hard to find even under magnification and there is no fluorescence.  It is about 2/10 of a mm larger in diameter than the 0.70ct.  A difference that is hard to spot as per the video so I think the D in this instance is the better purchase (being slightly lower in cost).

He picked the D in the end, as he didn’t want the stone too big!  He was happy that this came in under his £5k budget, resulting in a made-to-order ring that was £4,200.

Thoughts on D colour.

D is never a colour I go out of my way to try and sell, as it often adds an increment that visually doesn’t always justify itself.  But we will still come across Ds that are good value and well cut, and if a client specifically wants the colour, we’ll find them the right stone.

How do the diamonds compare?

Here’s your difference in this video.

The H is visibly larger, and looks whiter, because D is colourless and will pick up whatever colours are around it.  Beyond this, you get more of a visual as to why one is higher priced than the other, as you can see there is a lot more fire and brilliance coming out of the D.

Both are going to make beautiful rings. Both will hold their respective values over time.  But the H will require more care and maintenance than the D to stay looking good, the D will sparkle wherever there is light!  

There is the saying “if it sounds to good to be true, it probably is”..

Client C - Yellow Diamond Engagement Ring

He wants a yellow diamond.  He’s got budget for a larger stone, he is also motivated by the quality of the diamond.

I’ve written a blog on coloured diamonds here, it can be tricky what is described versus the reality of what that looks like.  Colours are graded as ‘Fancy’, ‘Intense’ and ‘Vivid’.  The latter are considered most valuable, but assessment skills here are variable (even with the GIA) and it is a specialist area. For example, these are both appraised as ‘intense’ but only the left hand stone meets that appraisal.  The right is just fancy coloured.

If it is difficult sometimes finding white diamonds, and fancy coloured stones can complicate the equation even more!  However, client and I discussed shapes for the design he had in mind, which made it easier to narrow down a brief. Even better - my buyers had just come back from a trip to India, and showed me this;

1.1ct Cushion shape with lots of crushed ice, slight rectangular shape (which actually works as setting design will square it off slightly) and a deep shade of yellow. Only thing this image doesn't show is the sparkle..

I took it immediately! You can see how special it was compared with a couple more intense stones in this image.

Cushion (1.1ct) next to modified square (1.01 carat), and radiant (1.03 carats) on right hand side. Cost per carat, the radiant was the most expensive stone as it was vvs2 clarity. But it wasn't nearly as pretty.

About 100 yellow diamonds were rejected by buyer before seeing that one. If my client hadn’t loved it, it would have ended up in a Bond Street store.

We made a full bespoke ring to house the diamond, and the ring ended coming in at £10,800 but was valued at £13,000.

Final Thoughts

It is always about needs versus budget. Every client we have is motivated by quality, they want good looking jewellery. Where the compromises come are in relation to the need for quantity as well. In this article, the biggest stone was also the lowest in price. The client was willing to make a number of compromises so we could deliver a good diamond for his budget. The clients who were unwilling to compromise selected smaller diamonds, of better appearance.

Want to discuss an engagement ring with us?

Get in touch and let us know more about your budget parameters, and what you think she’d like.

No items found.

Still haven’t found what you’re looking for?

If you are looking for something not covered by our services just get in touch. We’ll be able to answer your question right away and our first conversation won't cost you anything.