Natural Diamonds — GIA & IGI Certified, Direct from the Dealer
Loose, independently certified natural diamonds in every shape and size — sourced and priced at dealer level, not retail.
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The real value of buying direct.
A natural diamond formed over billions of years deserves to be bought properly — with the certificate in your hand and the pricing in your favour. Diagem trades loose certified natural diamonds across the full range of shapes, colours and clarities, sourced directly through the diamond trade.
Because we are dealers rather than a retail showroom, you are not paying for prime-location rent, glass cabinets or a sales floor. You pay for the stone. That single difference is why the same GIA or IGI certified diamond consistently costs less through Diagem than behind a retail counter, and it is the reason so much of our business comes from referrals.
We Don’t Just Show You Pictures.
Most online diamond dealers don’t hold physical stock — they show you catalogue images and order only after payment. At Diagem, you can book an appointment and inspect real diamonds in person before you commit.
Inspect Under a Loupe
Book an appointment and examine your shortlisted stones under magnification. What you see is exactly what you get — GIA & IGI certified, no surprises.
Vast Physical Inventory
We hold an extensive stock of loose certified natural diamonds across all shapes, sizes, colours and clarities — available for immediate viewing, not weeks of waiting.
Certificate in Hand
Every stone comes with its independent laboratory certificate. You verify the grade yourself before any money changes hands. That’s the Diagem way.
📞 082 551 2103 — Call or WhatsApp David directly
Think You Found a Better Price? Send It to Us.
As diamond polishers and cutters, we sit at the very top of the supply chain — no middlemen, no wholesale markup. In most cases we can beat — not just match — any like-for-like certified diamond quote you receive elsewhere.
Send us the quote with the GIA or IGI certificate details and we’ll do our magic and save you big.
Send Your Quote →Cut Is King — A Warning to Diamond Buyers
There are many diamond specifications that look impressive on paper but hide serious quality issues. Before you buy anywhere, know this:
Don’t Fall for the Price Trap
A nice carat weight, decent colour grade, good clarity and a GIA certificate in your hand — it all looks perfect on paper. But here’s what the certificate doesn’t tell you:
Price-only quotes are a trap. A diamond that looks like a bargain on paper could be a poor-quality stone that you’d spot immediately next to a well-made diamond.
Call David — even if you don’t buy from us.
David will look at any certificate and tell you honestly if it’s a good diamond or a cleverly-priced mediocre one. No obligation. That’s just how we do business.
Understanding what you are paying for.
Cut comes first
Cut governs how a diamond returns light. An excellent cut can make a smaller stone outshine a larger, poorly cut one, so we prioritise it.
Colour & clarity
We help you find the point on the colour and clarity scales where a stone looks flawless to the eye without paying a premium for grades no one can see.
Carat & shape
Choosing a fancy shape or a weight just below a round number can add visible size for the same budget. We will show you where the value sits.
Set it, or keep it loose.
Many clients buy a certified loose diamond from us and then commission a bespoke engagement ring or custom piece built around it. Others buy purely as a certified asset to hold. Whichever route you take, the diamond, the certificate and the value are yours. New to diamonds? Start with our plain-English diamond guide.
First-Time Diamond Buyer? Here’s Exactly How It Works.
Call David — he’ll walk you through everything in plain language. No jargon, no pressure, no obligation.
Call David
082 551 2103 — or WhatsApp. A real person answers. No robots, no call centres, no waiting on hold.
No-Obligation Chat
David explains everything in plain language. No pressure, no sales pitch — just honest advice from 25+ years in the diamond trade.
View the Diamonds
By appointment at our Johannesburg offices. We can also arrange to meet you in Cape Town.
Design & Approve
For bespoke jewellery, David consults with you at every stage. You receive photos throughout — nothing is a surprise.
Delivered to Your Door
Fully insured courier anywhere in South Africa. No need to travel — we bring the diamond to you.
“Anywhere in South Africa. Real diamonds. Real people. Real simple.”
With over 25 years in the South African diamond trade, we leave no stone unturned to find exactly what you're looking for. Every enquiry is handled personally by David — no chatbots, no automated responses. Real expertise. Real service.
📞 082 551 2103Let’s talk →
Frequently asked questions
Are your natural diamonds certified?
Can you source a specific diamond for me?
Which diamond shapes do you supply?
Will I really pay less than a retail jeweller?
Looking for a specific diamond?
Tell us the shape, carat and budget you have in mind and we'll source certified options for you to compare. David replies personally.
Let's find your diamond.
Speak to a dealer, not a salesperson. Get an honest quote with no obligation.