08:00 – 16:00

Monday to Friday

(021)761 1746

Welcome to The Gem Lab, we have over 30 years of expertise
September 27, 2021

08:00 – 16:00

Monday to Friday

(021)761 1746


Consistent Grading Standards

The ICSL system allows us to grade each parameter in 5% increments.

Gem Alert – Fake Rough

The only way to be completely sure that what you have bought is what you think you’re buying, is to have it checked and certified by an experienced, objective gemmologist. No matter who you bought it from.

Gem Alert – Lab Certificate Fraud

I founded The Gem Lab because it’s important to me (and to you!) that the gemstones our clients buy are the genuine article. The only way for a jewellery customer to have real confidence in what they buy is to have a certificate of authenticity with the gemstones they buy.


This gem alert is an urgent one. The latest con artist is an outright crook! He has already tried to pass a synthetic diamond off as natural in both Durban and Cape Town. He also has coloured stones and even glass in his arsenal, all ready to be sold to an unsuspecting buyer.

Gem Alert – All That Glitters

It’s always interesting to me that con artists and fraudsters seem to keep repeating the same tricks. It could almost be amusing if it weren’t for the fact that innocent and unsuspecting jewellers are being duped into purchasing and even reselling fake gems.

What is the colour of your gemstone really?

Consider an excellent final-grade-quality 1.00ct natural ruby. The wholesale price is $8100 per carat. The same quality pink sapphire will wholesale for $5 200 per carat. That’s a pretty substantial difference! Under daylight it is a pink sapphire … but under tungsten lighting, it would be a ruby. In other words, a single light bulb could make a $2 900 (R43 500!) difference in the final price.

Gem Alert – Coated Topaz

Gem enhancement has been practised for centuries. As long as people have been finding and selling precious stones, they’ve been looking for ways to get more from each sale. In fact, one could argue that this very goal is what motivated the first jewellers to cut and polish the earliest stones!

Basic Gem Identification Courses – May

Our popular Basic Gem ID courses are always in demand. So this May we’ll be running THREE Gem ID workshops – each at the special low price of just R1900 per person. This bargain rate includes tea and coffee, a light lunch … and a treasure chest of knowledge.

Jewellery and Gem Valuations

I started The Gem Lab to provide a unique service to the gem and jewellery industry, which includes gem and jewellery valuations. This is important because we don’t want to be found selling stones that aren’t authentic, or under- (or over!) insuring a precious stone.

Valuing Coloured Gemstones

Valuing Diamonds — Diamonds are graded according to an international grading system. This system ties in to an accepted pricing guide. And this is why traders prefer lab-graded stones: it’s possible to know exactly what you’re working with.

When gem laboratories grade diamonds, we look at four distinct characteristics. These let us determine the grade, which in turn helps us determine the price.