TYPES OF DIAMONDS

TYPES OF DIAMONDS

Pink Diamonds

The pink diamond is the world's most rare and valuable diamond.The Argyle mine is the world's foremost source of unrivalled intense pink diamonds, producing 95% of the world's supply. However, an extremely small proportion of Argyle Diamonds production is Pink colour, in fact less than one tenth of 1% is classified Pink.

The legend of Argyle pink diamond has grown over the past ten years. At the 1989 Christie's auction in New York a 3.14 carat Argyle pink sold for $1,510,000. Privately, Argyle has sold pink diamonds for up to $1 million a carat.

For years the white diamond was considered the world's most beautiful diamond, until the discovery of the Argyle mine heralded the arrival of the Argyle pink diamond. Never before had pink diamonds displaying such intense shades of colour been seen. The pink diamonds of India, Brazil and Africa were characteristically light in colour and paled even further when placed beside the intensely pink Argyle diamonds. The natural colour diamonds have in fact been around as long as the classical whites but in much smaller quantities and never in great demand.

The Argyle pink diamond comes in shades ranging from delicate pastel rose to robust raspberry and full-blooded purple-reds. The prices per carat are determined by the intensity of colour. Argyle selects only its most vibrant pink diamonds for polishing at its head office in Perth. There, the stones are polished in a wide range of cuts, such as round brilliant, marquise, oval and pear, to enhance their natural beauty. Polished pink diamonds are available in the same size ranges as traditional commercial sizes.

Once a year, Argyle Diamonds issues a special release of outstanding pink diamonds that are sold by special bids in the international and invitation-only, Pink Diamond Tender.

White Diamonds

White diamonds are produced by mines all over the world in a wide variety of shapes and sizes. The white diamonds recovered from the Argyle mine are particularly brilliant and of high quality.

White diamonds with secondary pink color

The Argyle mine also produces white diamonds with secondary pink colour that command a higher price per carat. In an effect similar to that described of pink champagne diamonds, the white diamond will display slight to bold flashes of pink when viewed from the top. A higher price is commanded for pink secondary colour depending on its depth and strength, because pink is one of the most rare colours found in diamonds.

Champagne Diamonds

Champagne diamonds are naturally coloured diamonds that are produced in a wide range of colours from light straw to rich cognac.

The 4C's of colour, cut, clarity and carat weight apply to coloured diamonds just as they do to colourless diamonds except the intensity of colour, not lack of it, plays a greater part in the valuation.

Argyle Diamonds created the following scale specifically for champagne diamonds. The diamonds are graded on a C1-C7 colour scale. C1 and C2 represent light champagne, C3 and C4 medium champagne, and C5 and C6 dark champagne. The fancy cognac diamond is graded C7.

Pink Champagne Diamonds

Attractive champagne diamonds with secondary pink colour are also available and command a higher price per carat than champagne diamonds. These stones display slight to bold flashes of pink in their fire.

Argyle Pink Champagne Diamonds are available in three ranges of shades, from light pink champagne to medium and dark pink champagne.

As pink is one of the rarest colours found in diamonds, even secondary colours demand a higher price depending on depth and strength of colour.

Yellow Diamonds

Fancy yellow diamonds come in a broad range of shades ranging from light yellow to a rich canary colour.
A limited quantity of fancy yellow diamonds is recovered from the Argyle mine.

Blue Diamonds

Fancy blue diamonds are available in a wide range of shades, from the blue of the sky to a more "steely" colour than sapphire.
Limited quantities of fancy blue diamonds are recovered from the Argyle mine.

Formation

Naturally formed blue diamonds are hardly found. So, in today’s world various methods are adopted where blue diamonds are artificially produced. In such methods, ideal conditions under which natural blue diamonds evolve are created. Diamonds with dark blue shades are costlier than the normal ones. Because of its rarity, sapphire is increasingly becoming a strong competitor of the blue diamond, although it can hardly compensate for the elite class of the blue diamond.

Cuts

A blue diamond can be shaped differently. Cushion cut, heart shape, pear shape, octagon shape, princess cut and marquise cut are some of the popular cuts and shapes into which blue diamonds are molded.

Green Diamonds

Fancy green diamonds are also available. Usually, penetration of the colour is not very deep and is often removed during the fashioning of the stone.
A limited quantity of fancy green diamonds is recovered from the Argyle mine.

Diamond Simulants

Cubic Zirconia

Cubic Zirconia (CZ) is the most commonly encountered diamond simulant. All commercial CZ is formed in laboratories however, it is also found in nature. In both its synthetic and natural forms, CZ is colourless but colour can be introduced. A thermal pen tester can quickly and easily detect CZ.

Synthetic moissanite

Synthetic moissanite is a new diamond simulant to join the long list of products that imitate diamonds. Although moissanite is being marketed as a new unique, synthetic gemstone, some of its properties are close enough to those of diamonds to lead to confusion in the trade.

Natural moissanite was first identified in a meteorite crater at the beginning of the twentieth century however, most is produced synthetically as natural moissanite is very rare. Chemically, it is 'silicon carbide', also known as 'carborundum', which is widely used for abrasive purposes and for use in the electronics industry.

Synthetic moissanite is a diamond simulant like Cubic Zirconia however, it can be passed as a diamond by the widely used thermal pen testers because it has similar thermal characteristics to diamonds. However, it can be easily identified by other methods.
Black Diamonds

Black Diamonds are precious and rare possessions to be cherished as they fall in the category of man made diamonds that boast of a prestigiously huge production cost. Black Diamond is in great demand for the jewellery market.

Black Diamonds are popular in three forms that include:

1. Natural color diamond/ Carbonado
2. Irradiation treated diamond
3. Heat-treated under high temperature

Carbonado is characterized as a natural polycrystalline diamond that has its origin in the alluvial deposits in the Central African Republic and Brazil. This diamond appears black and is highly permeable and is used for diamond maneuvers. Carbonado being a natural polycrystalline diamond comprises no mantle-derived enclosures and its carbon isotope value is very low. It occurs in asymmetrical or rounded fragments and is rarely distinctly crystallized but reveals a strong luminescence induced by nitrogen content of the crystal and by openings existing in the crystal trellis. This feature is due to the radioactive process that existed in the formation process of carbonado. The source of natural black color is black colored elements such as graphite or iron minerals.