May's Birthstone Sees Green
30th May 2019
To end this rainy month of May, I digged in some information regarding this month’s birthstone.
Belonging to the Beryl family, emerald can range from light green, to rich and deep green: the stronger the color, the more valuable is the stone. Obviously, it stays a matter of tastes, some may prefer less intense emerald. The intensity of the color depends on the amount of chromium in the composition.
It is the color and carat weight which will mostly determine the price of the stone. The inclusions in an emerald are usually highly visible to the eye, so that they almost become a beauty criteria. The so-called “Emerald’s Garden” can create amazing effects in the stone which enhances its unicity and beauty.
The most common treatment to reduce these inclusions is fracture-filling with natural oils which can be more or less tolerated by jewellers.
Emerald's gardens, various inclusions' types.
The rectangular shape with step cut (called emerald cut) is the most privileged for this stone since it emphasizes its sparkles and reduces fissures’ risks. However it is also common to find cushion cut and oval cut emeralds in more creative creations.
Even with its durable structure and 7.5 value on the Mohs scale, it is a delicate stone that can easily be damaged and suffer from shocks. This is why it is not recommended to wear an emerald ring for everyday use except if the mounting and prongs are well protecting the stone.
A little bit of history…
We estimate the oldest emeralds to be almost 3 billion years old, let’s say that it’s a quite good longevity. It was in Egypt, back in 1500 BC, that we discovered them first. For her love for emeralds, Cleopatra took ownership of the mines and largely exploited them. Today, these mines are exhausted.
On all continents, emerald has always been very appreciated by the chiefs. From Incas to Maharajahs, European Kings and Asian Royalty, the emerald was seen as a protection and healing stone. Nowadays, it is a fascinating gem, symbolizing peace, serenity, fertility and luck.
Necklace from Imperial Russian Family.
Belonged to Empress Catherine the Great.
1 Pear Cut Emerald of 75 carats.
The Greville Emerald Kokoshnik tiara, Boucheron, 1919. Worn by Princess Eugénie for her wedding, 2018. 1 Center Cabochon Cut Emerald of 93.70 cts.
Maharajah Necklace by Cartier.
17 Step Cut Emeralds totalling 277 carats.
A little bit of geography…
Emeralds can be found in many regions but the most popular mines are located in Colombia, Brazil, Afghanistan and Zambia. Colombia contributes to 50% of the world emerald production. Colombian emeralds are known to be the highest quality in terms of colors’ depth. On the contrary, Brazilian emeralds usuallly have a yellow hue which makes them look lighter.
Lately, African mines also get into competition with their smaller stones but of beautiful tones.
Emerald Mining Sites Map.
Below are two major emeralds: one is mounted on a ring and has an impressive heritage, while the other one is a rough stone which achieved extraordinary carats weight.
The Rockefeller Emerald Ring, by Raymond Yard
Set with an octagonal step-cut emerald of 18.04 carats
Estimate: $4 M USD - 6 M USD
Sold for: $5,5 M USD
--> $30.6 K USD per carat, record for an emerald
Buyer: Harry Winston
Christie’s - Auctions June 2017
The Bahia Rough Emerald
Approx 180.000 carats
From Brazil, Carnaiba Mine
Discovered in 2001
About 380 kg
Estimated at $400 M USD
Center of a dispute regarding ownership, trial is still in progress. One of the biggest rough emeralds ever found.