By Mark T. Cartwright
The vivid yellow of this diamond is only in your mind…literally. Colours are a significant part of our experience as humans and a huge part of what we do as professional gemmologists and appraisers. We describe hue, tone and saturation, overtone, brightness, and intensity, and we hope those relying on our observations and words can or will interpret them correctly. However, verbiage aside, what do we actually understand about colour and the factors affecting how we perceive it? I’m not an expert by any stretch of the imagination, but my investigations of this subject have provided me with a much greater appreciation of the complexity of what I’d once believed should be a simple process: create an environment to accurately see and describe colour.