January's Birthstone ~ Garnet

While researching for this blog post, I came across something I didn't know and is really unusual.  I know Garnets are found in a variety of colours and I know that most gemstone colours are due to the presence of certain minerals.  What I didn't know is that Garnet is not a single species but several species and varieties and that you cannot get a "pure" Garnet (they all have the same crystalline structure which makes them all Garnets) ~  you really do learn something new everyday!

The colour of the Garnet depends on the blend of varieties, these are:

Almandine is the most common type of Garnet and comes in a wide range of colours. The purest found was 80% almandine

Andradite is very rare and has more fire than a diamond! This has been found at 95% pure.

Grossular are rarely dark or red but are light to medium in tone.  They come in every colour including colourless but never blue. The purest found was 80% grossular.

Hydrogrossular are usually blueish-green but sometimes pink, white or grey and always opaque (there is some debate as to whether hydrogrossular can be classed as a garnet)

Pyrope is a red that rivals ruby although it is very dark. The purest found was 80% pyrope, 15% almandine and 2% other garnet

Spessartite comes in a range of oranges and is quite rare. One of my favourites! This has been found at 95% pure

Uvarovite is the rarest in the Garnet family and is a beautiful green that rivals Emeralds

Rhodolite Garnets are distinctly purplish and are a blend of pyrope and almandine, while Malaia is a blend of spessartite and pyrope.  One that was discovered in 2007 in Madagascar is an almandine and pyrope mix but this one changes colour in artificial light ~ blue that change to red with flashes of purple!

Rhodolite Garnet

In the last 50 years, new blends have been discovered in East Africa and there's no reason to believe that there will be more to come.  Exciting news for the gem world, jewellers.....and January babies!

December's Birthstone ~ Zircon

If I say Zircon to you, what do you think of?

I'm guessing you would fall into one of two camps......1 ~ never heard of it......2 ~ isn't that cubic zirconia??

Zircon and Cubic Zirconia are very different.  CZ is a lab created stone that is used as a diamond substitute along with Moissanite, whereas Zircon is a natural gemstone.  Zircon has such similar properties to diamonds that the two were often confused.  

Zircon comes in almost any colour you can think of, from white/colourless to pinks to blues to yellows to oranges to violets and everything in between! My personal favourite is Cognac Zircon, such a lovely rich colour.  Green is the rarest and therefore very expensive. 

An example of green Zircon can be seen in the George Pendant.  This is a huge 43.79 carat natural green Zircon (virtually all Zircon is heat-treated to enhance the colour) from the Ratnapura mines in Sri Lanka, and was cut  by George Cravoshay and set into this pendant by his wife, designer Paula Crevoshay.  It's large size and the fact that it has not been treated makes it incredibly rare and currently sits in the Smithsonian.

Gemstone of the Week!

Have you seen this beauty in the news this week?

This huge diamond started out as a 404.2 carat rough diamond mined in eastern Angola in February last year.  It's now a 163.41 carat, flawless, D-colour, emerald cut stunner.  It took six months to polish the diamond down after months of analysis, by master diamond cleaver 80 year old Ben Green, respected as the number one cleaver in the world.

The diamond was then set by a jewellers in Geneva called de Grisogono into this beautiful necklace, alongside emeralds and more diamonds and took over 1700 hours to create!

It's going to go under the hammer at Christie's in Geneva with a guide price of £23 million.....any takers?!

Gemstone of the Week ~ Topaz!

And so we come to November!  You lucky November babies have two stunners as your birthstones and this week it's the turn of........Topaz!

The most common colours of natural, untreated Topaz are pale yellow, brown and grey as well as pastel shades of green and pink.  As these are pale, most Topaz are treated through irradiation and/or heat to produce those vivid colours we know and love!  The most popular are the three stunning blues ~ a deep blue is known as "London Blue"; a highly saturated medium blue is known as "Swiss Blue"; and a bright light blue is called "Sky Blue"

Imperial Topaz, with its distinct peach, pink, orange or champagne hues, is  the rarest topaz variety. It is mined in the Ouro Preto mines of Minas Gerais, Brazil and deposits were also found in the Urual Mountains in Russia. In fact Imperial Topaz was named in honour of the Russian Tsars of the 17th Century who prized its luxurious golden-sherry hues. Today Imperial Topaz is classified as a very rare gem!

It was discovered over 2500 years ago and has more folklore and legend surrounding it than any other gem. It is said to attract love and fortune, protect against enemies an is even thought to aid with willpower to lose weight when worn with moonstone!

The Greeks believed Topaz gave them strength, relieved insomnia and restored sanity ~ sounds perfect for today's hectic lifestyle!  They also thought it had supernatural powers and could make it's wearer invisible

Topaz became a talisman of power in Ancient Egypt, protecting it's owner from harm.  The Egyptians thought it received its colour from Ra, the Sun God.

Topaz is a great gem to wear in jewellery as it's strong and durable.  It's also pleochroic, a fabulous term that describes the different colours you can see in a gemstone as it's moved in the light eg red topaz can show reds, pinks and even yellows.  Get in touch if you would love to add Topaz to your jewellery collection!

Gemstone of the Week ~ Tourmaline!

You lucky October babies not only get Opal as your birthstone but also Tourmaline

Tourmaline is one of those gemstones that has loads of different varieties.  The name comes from the Singhalese word turamali meaning "gem pebbles".  I quite like that :-)  Why are they called gem pebbles I hear you cry! They're called this because the rocks in which they most often form are not as resistant to weathering as tourmaline is and so they can be found in gravel deposits as little gem pebbles.  

So, let's get onto these different varieties.  I'm going to introduce you to some of my favourites.

This is a Tourmaline you don't see very often and I have no idea why.  It is colourless and known as an Achroite Tourmaline.  

Next up is the gorgeous Rubellite Tourmaline ~ just look at that colour!  Rubellite Tourmaline shades range from pale pink to shocking red.

This blue Tourmaline is known as Indicolite.

Now this has to be one of my all time favourites! Paraiba Tourmaline is quite new to the gem world.  It's neon colour comes from the copper contained within it.  Isn't it stunning?

This type of Tourmaline makes me smile every time I see it ~ Watermelon Tourmaline! Yes, this is completely natural and is known as colour-zoning.  When these crystals are sliced across, you get a red or pink centre surrounded by a rim of green.

Gemstone of the Week ~ Halleys Comet Opal!

I've written about opal a few times now and, as we're in October and Opal is one of it's birthstones, I'd thought that I might tell you about one Opal in particular.

This Opal is called the Halley's Comet opal and no, it didn't come from a comet although when I heard about it, that's what I thought too! After all, Peridot has been found in asteroids so it wouldn't be too much of a stretch :-)

It's called Halley's Comet as it was found in November 1986 in Australia as the Comet was passing through the southern skies at the time it was discovered and is only visible every 75 years.  Five Australian miner's known as the "Lunatic Hill Syndicate" found the gem, the largest uncut black opal in the world, at an open-cut mine near the famous Lightning Ridge in New South Wales.   It weighs nearly 2.000 carats (!), is about the size of a man's fist and is thought to have formed around 20 million years ago, phew!  The Syndicate was made up two brothers and a small company that provided earth-moving equipment.  "Lunatic Hill" got it's name back when mining first started at the site.  Opals could be found just a few feet below the surface in the shallow flats below the hill so that's where the most experienced prospectors stayed.  Why would you need to go to the top of the hill?  Only a madman would start up there, you'd have to dig for a very long time to find anything.  But this is exactly what this syndicate did and the Halley's Comet Opal was found 20m below the surface!  Just goes to show, just because someone thinks your're mad to do something, doesn't mean you're wrong!