We are able to source nearly every type of mineral or crystal commonly used in jewellery from Alexandrite to Zircon. See below for more information on the most popular precious and semi-precious stones or visit us for a free consultation. We provide free information with no obligation. To see our birthstone chart, click on the link below or scroll down to the bottom for a simplified table.

For a downloadable PDF of our birthstone chart with pictures, click here

Gemstones are generally devided into two sub-devisions: Precious and Semi-Precious stones. There are only four types of precious stones; diamond, sapphire, emerald and ruby. Some sources add tanzanite to this catagory due to its high price, but others argue that tanzanite can not be added since the stones require heat treatment to bring forth their colour. Everything else (for the moment including tanzanite) is regarded as semi-precious. Coloured gemstones are graded in much the same way as diamonds, only more attention is paid to the colour intensity, hue and the dispersion of the pigment within the crystal structure. Coloured gemstones can only be accurately graded by professional gemmologists. We are able to acquire certificates of authentication on any coloured gemstone at a charge. Contact us for more information.

Precious stones

Diamond

In general, diamonds are the most expensive gemstone on the market. Certain rare and exceptional specimens of other gemstones may fetch a higher price per carat, but on the whole, diamonds are the most expensive. Diamonds consist of almost pure carbon, super heated under extreme pressure in the earth's mantle until it crystalizes and is brought close enough for us to mine in the earth's crust by deep volcanic eruptions, which is why most primary diamond deposits are near live or extinct volcanoes. The word diamond itself is derived from the old Greek term adámas, which means "unbreakable", but contrary to what this may imply, diamonds are not unbreakable. They are certainly very hard and resistant to scratching (making it the only stone often used in jewellery that really does last a lifetime), but the formation of the crystal structure has such a clear grain, that it will split in two if you hit it at the right angle with the right amount of force.
Diamonds can be found in nature in almost any colour. The colour is created inside the crystal structure either through natural irradiation (e.g. natural green diamonds), caused by prolonged exposure to the sun (only in secondary deposits and it takes a couple of million years by the way), or because of the 'contamination' or inclusion of another chemical e.g. boron (blue), nitrogen (yellow) etc.
Not all diamonds mined are of gem quality though. Because of its hardness and high thermal conductivity, diamond is used in industrial porcesses from scientific experimentation to drill bits and other abrasive tools. To clarify what is regarded as a "gem grade" diamond, how they are graded and more information, click here.
 
Sapphire & Ruby (Corundum)
 
 
Sapphire and Ruby are two different colour variations of the same mineral - corundum (Al2O3, or Aluminium Oxide). Through history, both have been regarded as regal and sacred, the only difference really is the colour. The word 'ruby' is derived from the Latin word for red, rubeus, while the word 'sapphire' is taken from the Greek word for blue. As one would therefore assume, in the days before the identification of corundum as a mineral at the start of the 19th century, the word ruby applied to the red variant (though at the time garnet and red spinel were also regarded as ruby), while the word sapphire was used exlusively for blue stones. Today the word 'ruby' still applies to the red variant only while the term 'sapphire' is used for every other colour variant, though in some cases sapphires in a colour other than blue might sometimes be refered to as 'fancy coloured' sapphire.
 
Being second in hardness only to diamond, corundum is a very durable gem and a fine choice for both jewellery and industrial processes. Synthetic production of corundum in laboratories has been possible for quite some time, and the process is so effective that you'll find it in the most obscure places, from watch glasses to ball-point pens. These synthetic stones are identical in composition and crystal structure to that of natural sapphire and ruby, though they won't fetch nearly as high a price as their natural counterpart.
 
Varieties
 
Ruby:
 
An exerpt from Renée Newman's Gemstone Buying Guide: How to evaluate, identify, select and care for colored gems (International Jewellery Publications; 2003) reads:
"In 1896, German mineralogist Max Bauer wrote: A clear, transparent and faultless ruby of deep red colour is at the present time the most valuable stone known. Today diamonds have surpassed rubies in value, but Bauer's description of a top quality ruby is still valid...
...Large rubies have sold for as much as $200,000 per carat, but good rubies with inclusions in the 1-carat range are available for $3000-$4000 per carat. You can also find opaque rubies for as low as $10 per carat. A premium may be charged if a high grade stone originates from Mogok - " Myanmar (Burma) " - or shows no evidence of heat treatment, providing it has a lab report from a respected lab. Rubies are normally heat-treated to improve color and/or clarity. Diffusion treatment, large glass fillings and red oils or dyes greatly affect the value."
 
Sapphire (blue):
 
Though mining in the area has been limited for quite some time, the most expensive sapphires seem to come from Kashmir, followed by Burma and Sri-Lanka. However, Madagascar has surpassed its competitors has the major source. Sapphires are also found in Thailand, Cambodia, Australia, India, Montana, China and various African countries. Stones that originate from Australia are usually lower priced because they tend to be less transparent and overly dark. There are many different opinions as to what is regarded as the most valuable colour variation. Whilst some prefer a violet tone and others a deeper blue, all dealers seem to agree that grayish and greenish overtones and stones that appear black or opaque are of lesser value. In our opinion, a good colour sapphire is a deep, clear blue with a high transparency. The colour is very accurately imitated by lab creation so most created sapphire stones display this colour. Natural sapphire is usually heat treated to improve colour and the outer surface is sometimes darkened by diffusion, but this kind of treatment must always be stated on lab certificates.
 
Padparadscha:
 
This colour variety is the most prized of all the fancy sapphires and by far the rarest colour veriation of corundum. It has a pinkish-orange hue. Though some dealers might sell an orange sapphire as a padparadscha, both orange and pink must be present for it to be considered a true padparadscha. Some dealers insist that the colour must be natural, but whether or not it was treated should be stated on the lab certificate. This is an extremely rare gem and is prized by connoisseurs and collectors world wide.
 
 
Pink sapphire:
 
In western countries pink sapphires are treated as a unique stone with its own criteria, but some dealers, especially in eastern countries, prefer to class it as a ruby. This is done because rubies generally fetch higher prices than sapphires even though, as a lower grade ruby, it can sometimes sell for less than it would if it is marketed as a fancy sapphire.
 
Other colour verieties:
 
The most commonly found fancy sapphire is the yellow veriety, though it is surpassed in value by orange (if untreated). Green is considered the least valuable (of which Australia is the largest source). Purple diamonds are also found, though they do not fetch prices as high as orange. Ceylon sapphires originate from Sri-Lanka and usually have a light purplish-blue hue, much the same colour as that of the lower grade tanzanite found in retail jewellery stores. White sapphire is created by heating stones with very light colour that would not be regarded as a good colour. They are used as a subsitute for diamonds and have become quite popular in recent years.
 
Star phenomenon:
 
Star sapphires and rubies have included impurites that bend the light to create a star. They are usually grayish or maroonish and tend to be less expensive than transparent stones of good clarity.
 
 
Emerald (Beryl)
 
 
In her book Gemstone Buying Guide: How to evaluate, identify, select & care for colored gems (International Jewellery Publications; 2003), Renée Newman writes:
 
"In its pure form, beryl is colorless. But thanks to the presence of impurities, this mineral can be blue, green pink, red, yellow or orange. If, for example, traces of chromium and/or vanadium are present, the result may be an emerald. A trace of iron can turn the beryl into an aquamarine, whereas a bit of manganese adds a pink or orange color to the stone.
Of all the beryls emerald is the most highly valued and has the longest history. Some evidence indicates that emerald deposits in Egypt may have been exploited as early as 3500 BC. However, most of the Egyptian emeralds were pale, drab and heavily flawed. It wasn't until the 1500's when the Spanish invaded the Americas, that Europeans realized how beautiful an emerald could be and vast quantities of Columbian emeralds were brought to Europe by the conquistadors.
Aquamarine and yellow beryl have also had a long history, but it's hard to determine when they were first used. The orange, pink and red beryls have only been recognized as gems since the early 1900's."
 
Emerald:
 
Whilst minerologists argue that beryl can only be labeled 'emerald' if the colour in the stone is caused by included chromium, some dealers will class vanadium beryl as emerald regardless. The origination of the colour is irrelivant however, since the market does not make a distinction with regards to pricing. Good quality emeralds should have a saturated green colour, be transparent and eye clean to fetch a high price. Usually, the deeper the colour, the more the stone will be flawed with inclusions and cracks. Finding an emerald with excellent colour of high clarity and transparency is very rare and these stones are usually very expensive. Emeralds are often treated in various ways to improve the appearance of inclusions and cracks with oil, wax or resin, and this is regarded as acceptable as long as it is disclosed. It is very difficult to tell what kind of treatment, if any, has been done without a lab certificate. The fillings are not always stable and retreating is sometimes necessary. Most good quality and the highest quantity of emeralds are produced by Columbia. Other countries of origin include Zambia, Zimbabwe, Brazil, Pakistan, Afghanistan, Russia, Australia, India and North Carolina (USA). Emeralds are extremely soft and prone to scratching and breaking, so much so that some setters refuse to set them due to the high risk of breakage.
 
Aquamarine:
The name is derived from latin and means 'sea water'. In antiquity they were most popular as a greenish blue stone. The modern market however, prefers to heat treat it to remove the green, producing a permanently-coloured blue stone. It is still rather soft, but because of its high transparency and clarity is more durable than emerald.
 
Morganite (pink, orange and purple):
 
This veriety is found in California, Madagascar and Brazil and is described as a pale pink stone, though specimens with an orange or purple over tone are not uncommon. It has become quite popular in recent years and can fetch relatively high prices.
 
 
Red beryl (Bixbite):
 
Sometimes erroneously referred to as 'red emerald'. Discovered in Utah in 1906, this rare gem is not easily found in the market and most often sold to collectors.
 
 
Heliodor (yellow beryl):
 
Aslo called golden beryl. Mined mostly in Brazil, Russia and Namibia.
 
 

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For a downloadable PDF of our birthstone chart with pictures, click here

 

 

Month 15th to 20th Centuary US 2012 Britain 2012
January Garnet Garnet Garnet
     
February Amethyst, Hyacinth, Pearl Amethyst Amethyst
     
March Bloodstone, Jasper Aquamarine, Bloodstone Aquamarine, Bloodstone
     
April Diamond, Sapphire Diamond Diamond, Rock Crystal
     
May Emerald, Agate Emerald Emerald, Chrysoprase
     
June Cat's Eye, Turquoise, Agate
Pearl, Moonstone, Alexandrite
Pearl, Moonstone
     
July Turquoise, Onyx Ruby Ruby, Cornelian
     
August Sardonyx, Cornelian, Moonstone, Topaz Peridot Perdot, Sardonyx
     
September Chrysolite (Peridot) Sapphire Sapphire, Lapiz Lazuli
     
October Opal, Aquamarine Opal, Tourmaline Opal
     
November Topaz, Pearl Topaz, Citrine Topaz, Citrine
     
December Bloodstone, Ruby Turquoise, Zircon, Tanzanite Tanzanite, Turquoise