Jewellers' Network

Category: Gemstones

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 jeremy@gemlab.co.za

Warm regards,
Jeremy


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.

Apatite
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…


Zultanite

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…


Inclusions – African Gemmological Laboratory

Inclusions African Gemmological Laboratory

In gemmology an inclusion is a clarity characteristic, enclosed within a gemstone, or breaking the surface from the interior.

Inclusions are normally perceived as being a negative feature in a gem as they usually devalue a stone, except in the case of ‘horsetail’ inclusions in demantoid garnets and phenomenal gems where the inclusions cause the phenomena.
Continue reading…


Coloured Stone Grading – Part 3

Clarity

Welcome to part 3 of our mini-course on coloured stone grading. Last week we looked at the key role colour plays in assigning a grade value to a gemstone. Today, we’re diving into clarity. Continue reading…


2017 – New Beginning

New Courses, New Prices, and a New Approach to Learning Gem Identification

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The value of a gemstone is tied to a number of factors. Telling what these are takes a trained eye. A gemstone is only worth what it can be sold for, and that depends heavily on whether its authenticity can be proven. The best way to prove the worth of the stones you’re selling is to ensure each one is certified by an internationally recognised professional certifying body. Including a printed certificate of authenticity with your gemstones means you’ll be able to close more sales – and for a higher value.

Continue reading…


GEM CUTS

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Point cut

This earliest of diamond “cuts” simply involved polishing away any blemishes on the faces of a diamond octahedron. Legend has it that the association of diamond with love came from the practice of French courtiers to use a point diamond to write messages on inconspicuous palace windows arranging assignments, hence engagement rings.

Table cut

The table was a very early and practical diamond cut. It merely amounted to grind-ing and polishing away a heavily included or damaged point of a diamond octahedron.

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The Garnet Group

The garnets, a large and rather complex family group, may vary considerably in their chemical composition, physical and optical properties.

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For the gemmologist this means that there is an additional step in the identification process. Firstly he must determine if the properties of the unknown place it within the garnet group?
Secondly to which species does it belong and then finally what variety is it? 

Continue reading…


Add some Christmas Sparkle – Zultanite

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The term “diamond in the rough” has become a familiar companion in our daily lexicon. It’s used to describe a number of different scenarios – anything from a surly-seeming character who’s really quite charming once you get to know him … to a thing of great value, which has yet to be discovered.

Zultanite falls squarely into the latter category. It’s one of those almost-forgotten gems that, if marketed properly, can add some genuine sparkle to your sales this Christmas.

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Natural top – synthetic bottom

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Last week I showed the star rubies and sapphires that can be grown using the Verneuil process. They can be exquisitely beautiful, but no less fake for all that. It’s a classic case of true beauty being more than skin deep!  

It’s also very good reason to make sure you get your gemstones checked before
you sell them to unsuspecting customer. Better yet, if you can, get them checked before you buy them!

Rubies and sapphires are not the only gems to get the synthetic special treatment. Really, anything that has integral value will soon find itself the subject of knock-offs, copies, look-alikes, wannabes, and fakes.

Continue reading…


Gem Alert – FAKE ROUGH

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Finely polished tourmaline is simply exquisite. Glinting happily in every hue of the rainbow, it’s easy to see why this exquisite stone is gaining popularity. Of course, as it becomes more popular, it becomes more expensive. The higher the demand, the higher the price. Unfortunately, the more valuable something becomes, the more tempting it is for the unscrupulous. So it’s no surprise that con artists have started peddling fakes, trying to pass it off as the real thing. (Although it is disappointing, of course.)

We came across an example of this just the other day, when a client bought a bag of rough tourmaline. Or so he thought. It was actually a bag full of glass. This rough is very convincing, though. It’s no surprise my client was duped into thinking it was the real thing.

Continue reading…


Gemstone Origins (Part 2 RUBY)

ATG

Ruby is generally found in a metamorphic environment especially in such rocks as granular limestone, mica or chlorite schists, however it may also occur as a constituent of aluminous igneous rocks. Ruby is a variety of corundum, which is the second hardest natural mineral after diamond. Being both hard and heavy gem corundum rough is most frequently recovered from placer deposits. Traces of chromium are responsible for the superb blood-red hue of fine material.

Continue reading…


Self-Serving Certification?

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Some jewellery firms issue their own certification. The idea is that this saves time and makes it easier for buyers to – well, buy.

The question is, can these firms really be trusted to give an unbiased certification?

Not long ago, I was asked to double-check the certification of a diamond. It had already been certified by the well-known establishment that sold it. When I examined the diamond, I found that the GIA (Gemological Institute of America) reference number had been lasered onto the girdle. That meant I could look it up online.

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Useful Information Gemstones

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Stone Setting & Style

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Communication is so important when a group of people are working together for a common goal. We all know what happened to the tower of Babel when God changed the languages of the workers. In that vein I thought we could go over some of the basic terms used in our trade in order to ensure that we all speak the same language. 

Continue reading…