Diamonds occur in an array of colours
– from pure whites and soft pinks and blues to brilliant hues of purple and red.
- No matter the colour, each diamond possesses a unique composition of chemical elements
- that have the power to dictate rarity, value and desirability.
- Read on to learn how nature creates the world's most radiant gems.
- White diamonds are the most common,
- falling into the largest colour spectrum on the Diamond Grading Scale,
- which begins with “D” colour, meaning totally colourless, and
- ending with “Z” colour, which is pale yellow or brown.
- The variable in this spectrum is the element Nitrogen
- a D colour diamond completely lacks Nitrogen,
- with the Nitrogen content increasing along the spectrum.
- The vast majority of white diamonds mined today have a large content of Nitrogen,
- which classifies them within the end of the colour scale.
- Diamonds that fall within the E – F colour range are rare, therefore more valuable,
- as their chemical composition and crystal structure is made up almost only of carbon
- with only traces of Nitrogen.
- Coloured diamonds contain impurities or structural defects within the chemical composition.
- In the case of yellow diamonds, nitrogen is incorporated into their carbon crystal structure.
- These nitrogen impurities give a diamond its yellow colour as they modify light and
- absorb the blue part of the visible spectrum.
- Yellow diamonds that have a higher concentration of colour more intense than Z colour,
- as well as diamonds that exhibit colours other than yellow or brown,
- are considered “fancy” coloured diamonds.
- All fancy coloured diamonds follow the same colour grading scale:
- Fancy Light, Fancy, Fancy Intense, and Fancy Vivid.
- As the colour concentration increases within the stone, so does its value.
- Blue diamonds are caused by impurities of Boron, a rare element in the Earth’s crust.
- Many are modified with a grey secondary tone, or
- an uneven saturation with areas of colourless windowing,
- making natural blue diamonds with exceptional saturation and brilliance extremely rare.
Pink, Red & Other Coloured Diamonds
- What makes a pink or red diamond? This is actually an impossible question to answer,
- as there is no impurity that causes its colour,
- only the evidence that these diamonds have a mutation within their crystal lattice
- that alters the stone’s molecular structure.
- With enough of these “defect centres,” the diamond may take on different properties.
- For example, the diamond could absorb a certain wavelength of green light,
- resulting in a pink appearance.
- Other colours, such as green, purple and orange, occur from natural radiation and other common elements within the Earth.
- Diamonds are truly an anomaly of nature.