A gemstone's perceived colour is the product of the light it is viewed in. The true colour of a stone can only be seen in natural midday sunlight, as the sun's light carries the full colour spectrum visible to human eyes. Artificial lights only carry partial colour spectrums and usually at less intensity, causing the stone to appear darker and less detailed, and with an incorrect colour.
This is an important phenomenon to account for when viewing a gemstone via the internet. An online image has had its colour altered a minimum of three times: 1. by the artificial studio lighting 2. by the studio camera 3. by the viewer's computer monitor. No image viewed on a computer will be 100% accurate in terms of colour. With recent technology however, it is possible to broadcast a reasonably good representation.
Our controlled photography studio aims at producing images that are consistent with one another for accurate comparison between gemstones; and images that portray the gemstone as close as possible to its appearance in natural midday sunlight. We have found that recent high definition Plasma and LCD computer monitors produce excellent, nearly true-to-life images when they have been finely adjusted; and we present our images to be most accurate when viewed on those platforms.
The images below show the effect that different lighting can have on the apparent colour of a stone.