As the most concentrated form of wealth on the planet, natural coloured diamonds represent a very unique form of "crystalline art". The beauty and mosaic arrangement of transparent, reflected colours seen in the face-up direction of any polished coloured diamond is literally "indescribable", similar to looking at other natural coloured items, such as rainbows, butterflies, flowers, sunsets, etc. In natural coloured diamonds, their often indescribable beauty is due to the incredible number of inherent body colours that nature has instilled in diamonds, combined with the infinite assortment of mosaic colour patterns seen in the face-up direction of every polished coloured diamond.
Natural coloured diamonds occur in fourteen (14) visually distinct colours (hues), known as colour varieties (e.g., colourless, white, gray, black, violet, purple, pink, red, orange, brown, yellow, olive, green and blue). In addition, each of these fourteen colour varieties exhibit an incredible range of colours based on whether the colour is pure (e.g., blue), or if the main colour has a secondary colour (colour modifier) mixed with it (e.g., greenish blue, grayish blue, etc.). These secondary colours (hues) are known as colour modifiers. Nature has created a remarkable assortment of colour mixtures in diamonds, involving one modifier, or in some cases, more than one colour modifier (e.g., brownish yellowish orange, bluish gray-violet, brownish reddish orange-pink, etc.).
In addition to the basic fourteen colours and the numerous combinations of secondary colours, each coloured diamond also exhibits visual differences in the lightness (which can range from very light to very dark), and visual differences in the saturation (which can range from weak to very strong depending on the colour). Measuring these subtle differences with a portable optical instrument (such as a Rennilson-Hale Gemstone Colorimeter), then plotting the numerical colour data on 3-dimensional charts to determine the exact colour (hue, lightness and saturation), enables me to explain the intricate details of a particular diamond's face-up colour to a coloured diamond collector or investor.
Over the past thirty plus years I have developed a genuine passion for studying natural coloured diamonds and have devoted my entire career to measuring, photographing and studying these rare, beautiful and remarkable coloured gemstones. Each rough coloured diamond is an astonishing expression of what nature is capable of producing deep within the earth under a certain set of physical and chemical conditions involving extreme heat and pressure. Therefore, each diamond crystal has a unique story of how it acquired its particular colour from nature, often with a slight twist of fate, giving certain stones unusual and unique qualities of colour that often go unnoticed or unappreciated by the novice eye. Unlocking these mysteries of colour in diamonds is my passion, and then explaining these subtle colour differences to an interested collector is my reward.
"The face-up colour seen in a well-cut coloured diamond specimen appears to float across the stone, confined for an instant to a single facet, then another adjacent to it, and so forth as the stone is moved. Like an expensive sequined gown, a coloured diamond is an undulating, restless mosaic of reflected colours that captures the eye, stimulates the mind, and enlivens the spirit."
Collecting and Classifying Coloured Diamonds 1998