What are coloured (more commonly known as fancy-colour) diamonds?
These are diamonds that have a noticeable colour when viewed in the face-up position. Yellow and brown are the most common colours in natural-coloured diamonds, whereas pink, red, orange, green, and violet are quite rare.
What causes colour in diamonds?
A natural diamond is a rare form of crystalline carbon, so a diamond composed entirely of carbon, with perfect crystalline composition, will be colourless. However, diamonds that perfect rarely exist. Instead, most diamond crystals accumulate defects during their growth deep within the Earth. These defects modify the way light passes through the diamond. They can cause the diamond crystal to selectively transmit some wavelengths of light and selectively absorb other wavelengths of light. Because each wavelength of light corresponds to a different colour, this selective transmission and absorption determine the diamonds’ apparent colour.
For example, the colour pink in a natural diamond occurs when the crystal is subjected to extreme stress within the Earth, and these forces cause atom displacement. When light passes through these areas of displacement, red light is selectively transmitted, appearing pink when the transmission is weak.
Yellow diamonds get their colour through the presence of nitrogen during the formation of the stone.
Diamonds with a natural green colour developed that colour while they were underground, in rocks that contained small amounts of radioactive material such as uranium or thorium. As the radioactive materials decayed, they emitted radiation that penetrated the nearby diamond crystal. Although a green colour in diamonds is usually caused by irradiation, it can also be caused by structural defects in the diamond's crystal structure, caused by the presence of nitrogen, hydrogen or nickel atoms.
Coloured diamonds are extremely rare.
It is said that 1 out of every 10,000 diamonds is fancy-colour. And of these, red is considered the rarest. In fact, it is estimated that only 30 pure red diamonds have ever been found!
Pink diamonds are extremely popular at the moment.
Like pure red diamonds, pink diamonds are also extremely hard to find. These stones are becoming increasingly popular among investors and collectors.
The Argyle Mine is now closed!
The Argyle Mine in Western Australia was considered the world’s most important source of coloured diamonds since 1985. It has held the distinction of being a great source of pink, red, and violet diamonds. It has been home to 90% of all pink diamonds mined. However, operations ceased in 2020, meaning that the value of pink diamonds is set to appreciate substantially.
Pink diamond prices have been appreciating.
Pink stones have undergone a whopping 600% increase in their value since 2005!
Coloured diamonds don’t depreciate easily.
In an annual Wealth Report, published by London-based property company, Knight Frank; the organisation found that the average price of coloured diamonds has increased by 111% overall in the last decade.
Investments are for everyone and coloured diamonds continue to break records.
You don’t need to be a millionaire to invest in coloured diamonds. These beautiful gems range in price from a few 1000 Rands to millions – it’s just a case of going with what works for you. Co-Founder and Managing Director of diamond retailer 77 Diamonds, Tobias Kormind says: “Diamonds are the next area for alternative investments.
The Pink Star was one of the most highlighted stones at the April Sotheby’s Hong Kong auction on April 4, 2017. The 59.6-carat stone was sold for a record-breaking $71.2 million!