Jewellers' Network

Category: Gemstones



Spinel, composition magnesium aluminium oxide, occurs in the same deposits and exhibits the same hues as the aluminium oxide gems ruby and sapphire so that for centuries it was confused with them. 

This was the case with the fine 170ct cabochon cut red spinel set above the Cullinan II in the Imperial State Crown of England. This is a stone with a long and chequered history. It was first recorded in the mid-fourteenth century as belonging to Abu Said, the Moorish Prince of Granada. Continue reading…

Feldspar by AGL


Over 50% of the earth’s crust is made up by a large group of rock-forming silicate minerals that we call feldspar. 

The name was derived from the German word ‘feldspat’ meaning ‘field rock’. Feldspar has many uses from ornamental stone carvings, granite counter tops and fine jewellery pieces to its use in the production of glass and ceramics as well as a component in some paints, plastics and rubber. In 2010 alone, about 20 million tonnes of feldspar was produced. Continue reading…

JPPE – Tanzanite


Found only in Tanzania, this African gemstone has a beautiful range of colours, from deep blue to light blue and lilac, indigo and violet. Continue reading…

Gemlab – What’s in a name?

Correct Identification Is The Name Of The Game! 

When she said that “a rose by any other name would smell as sweet,” Juliet was obviously not talking about gemstones! Her argument was that didn’t matter what name Romeo had, he was just as valuable to her. This might well be the case when it comes to true love, but the same logic can definitely not be applied when we talk about gemstones! Continue reading…


Citrine, the birthstone of November with the fire of the sun is known to bring hope strength, vitality and energy to the wearer.

This rich golden colour gem has made it a stunning summer birthstone jewellery gift.

Continue reading…

Gemlab – A Great New Course To Help You Make The Grade


Winter is over, and I know many people in the jewellery trade will be very thankful to see the back of it. For some of you, winter was a very bad season business wise. Yet strangely, it was a great time for others. I’ve been asking myself why this is. Why do some jewellers do really well, while others struggle?  Continue reading…

Opal and Tourmalines

Opal and Tourmalines are the modern birthstones for November.

Opal are unique because the spheres of silica diffract the light to give off an iridescence of colour making each one unique in its own way. This makes it wonderful birthday gift. Continue reading…

Exciting New Developments From The Gem Lab

GEMLAB banner ad

The Gem Lab has been providing a unique service to the gem and jewellery industry for over 25 years, and we are 100 percent committed to continuing to do so. But, as with any business, it’s important to stay on top of new developments – and, when it comes to the gemstone industry, there are always plenty! Continue reading…

Emerald and other varieties of Beryl

The occurrence of emerald is relatively rare because this mineral is only formed under very specific and unusual geological conditions.

Continue reading…

JPPE Manufacturing Jewellers

JPPE Manufacturing Jewellers
JPPE Manufacturing Jewellers is a Cape Town based family business that has been servicing the jewellery industry for 50 years.

Continue reading…

Sapphire – Birthstone of September

JPPE Cape Town Sapphires

As a symbol of Love and Purity, Sapphire makes one of the best birthstone gifts.

Almost as hard as a diamond and durable to wear everyday it makes a great alternative to diamond with engagement and anniversary rings. It’s found in most colours of the rainbow. Blue and Pink are the most popular choices.

Continue reading…

Save Tsavorite – Take our Basic Gem ID Course Now!

Oscar Wilde said many wise things, one of my favourite of which is “Life imitates art.” When he penned his now famous line in his 1889 essay, The Decay of Lying, he couldn’t possibly have known that over a century later, we’d be faced with imitation of a very different kind. 

Sadly, we are seeing far too much glass imitating tsavorite recently. This is a real tragedy, because tsavorite – the trade name for the emerald-green variety of Grossular Garnet that comes from Tanzania and Kenya – has become one of the most popular and expensive Garnets. It takes its name from the Tsavo National Park in the Serengeti, which is close to where it was first discovered. It was named by Campbell Bridges, its discoverer, and Henry Platt, president of Tiffany & Co. Continue reading…

Geminar by Gemlab

Come And Join Us At Our Geminar!

NOTE: We have one place available for the Practical Diamond Grading course from the 19th-21st July and the Basic Gem ID course on the 28th July 2017.

Regular readers of this newsletter may have picked up on the fact that not only am I personally passionate about all things relating to the fascinating world of gemstones, I’m equally passionate about stoking that enthusiasm and interest in others as well. Continue reading…

Jade, it’s varieties, substitutes and stimulants

Jade is a term used to describe two physically similar but chemically very different stones.

Whereas nephrite is a silicate of calcium and magnesium, jadeite is a silicate of sodium and aluminium. Sir Charles Hardinge, author of Jade Fact and Fable, proposed the names ‘amphibole jade’ for nephrite and ‘pyroxene jade’ for jadeite. While his suggestion was obviously meant to clarify the different nature of these materials it did not receive wide acceptance.

Jadeite generally exhibits cleaner brighter colours. It has a higher refractive index and is slightly harder and heavier than nephrite. Continue reading…

Upcoming Diamond Grading Course

The Gem Lab courses are becoming very popular and due to high demand, I have been asked to run another Practical Diamond Grading Course.

I am pleased to inform you that the next three-day Practical Diamond Grading Course will be held from the 19th – 21st July 2017.

Once you have completed the course you will be able to…
…have a better understanding of how the diamond industry works,
…answer questions like ‘blood diamonds’, diamonds as an investment, etc.,
…buy and sell diamonds with confidence,
…estimate the weight of diamonds set in jewellery,
…estimate the value of old cut diamonds,
…explain the 4C’s to customers,
and so much more.

For more information call me on 021 761 1746, or email

Warm regards,

Gem Alert – Fractured Synthetic Ruby

Synthetic rubies are giving the slip to those in the trade since mankind assigned value to pieces of shiny metal and brightly coloured stones, attempts have been made to duplicate Mother Nature’s handiwork.

The Verneuil Process of producing synthetic gemstones is the most common synthetic we see today.

Continue reading…

Invest In Yourself Today

Benjamin Franklin famously said, “The only thing more expensive than education is ignorance.” Profound, yes, and still absolutely true over two hundred years later. But improving our education doesn’t only mean attending school or university. As intelligent, curious adults, we should always be looking for ways to increase our knowledge and foster a love of life-long learning that enriches our lives and grows our minds.

Continue reading…

Blue hues

Blue hues – Arthur Thomas

Agate blue lace
Viable deposits of this attractive agate with its delicate lacy blue and white banding occur in both South West and East Africa.

This name, derived from the Greek for “I am misleading” is probably a reference to its marked resemblance to the harder and more valuable mineral, beryl.   Sapphire blue apatite is sometimes given the varietal name Moroxite it was produced as a by-product of emerald mining at the Cobra Mine, Phalaborwa. There are mines in Madagascar that produce apatite in a wide range of hues including the very collectible electric-blue and neon-green varieties. Continue reading…


The Turkish deposit remains the world’s only source of Zultanite (color-change, gem quality diaspore) and is recovered using only environmentally safe mining techniques.

Zultanite was named in honour of The Ottoman Sultans that ruled a vast empire for many centuries.

The GIA classifies Zultanite as a Type II transparent gemstone.  Zultanite almost always contains inclusions.

Continue reading…

Gemgold Gemstones

With more than 20 years of experience in the gemstone industry, GemGold Gemstones, is still going strong!   

What once started as a small business, with Andre de Klerk, buying and selling rough gemstones, has  flourished over time, into a substantial and reputable gemstone business.  Some might say the magic came to life, once Andre’s wife, Errolene, joined him.  Errolene quickly found her niche and specialised in the selling of cut gems, in the jewellery industry. Continue reading…