The Joys of Color October 02 2016
Color can often be the hallmark of a stunning gemstone. The Gemological Institute of America (GIA) and many jewelers across the world use a host of terms to describe these colors and a quick glance at them can often precipitate a state confusion. ‘Violetish blue/vB’, ‘Vivid’ and ‘Medium Dark’ are all terms that can be used to describe the color of a fine sapphire but what exactly do they mean? Informed purchases are often the best purchases and therefore a little knowledge on color would place you on a path to selecting the right gemstone at the right color.
A trip down memory lane to one of your art classes may shed light on what components constitute color. If you remembered that they were hue, saturation and tone, I’d say I’m quite impressed, well done! The three attributes are highly integrated and play a delicate role in producing colors across a wide spectrum from the faintest yellows to the darkest blues. When assessing the color of a gemstone, keeping these factors in mind can help you determine not only the make-up of it color but also why the jeweler may have proportioned the gem as it appears.
Hue generally refers to the initial impression of the gemstone’s basic color. The hue is best assessed ‘face-up’ with the table of the gemstone being perpendicular to your eyes. This can be done under white light or even a natural ambience and is often described as yellow, blue, green, red or orange. As mentioned earlier, some hue descriptions may state ‘violetish blue/vB’ or ‘reddish orange/rO’. This is usually as a result of a color combination being emitted from the stone perhaps through a phenomenon known as ‘color zoning’. Gemstones with a pure hue which are undisturbed by any others are generally regarded as more valuable than those with a mix of hues. For example, blue sapphires are generally preferred as pure blues or ‘violetish blues’ as opposed to green secondary hues.
Tone is the second dimension of the world of colors. From a visual perspective, it runs from white to black with a fine gradation in between these two extremes. In terms of the tone scale issued by the GIA, gemstones can be found to be very light (2), medium (5) or very dark (8). It is important to note that is a separate attribute when determining color but it is deeply intertwined with hue and saturation such that a gemstone may have a light tone but the interaction between hue and saturation may make it exude a darker tone. In terms of sapphires, the finest range from medium light to medium dark as is characteristic of many famous Ceylon sapphires such as the Logan sapphire. You can also view our featured sapphire bracelet showcasing a stunning display of tone here.
The final character is built on saturation. This refers to intensity or strength of color presented by a gemstone. The GIA has issued a scale for saturation as well and it runs from (1) to (6). Warm (reds and yellows) and cool (blues) colors have similar descriptions in the scale from (4) to (6) ranging from ‘moderately strong’ to ‘vivid’. However, as saturation weakens for warmer colors they appear as brownish (1) or as grayish (2) for cooler colors. The finest sapphires, of course, will generate a saturation from (4) to (6) with vivid being the most desired. This two tier scale helps to add a standard across the global gem industry and ensures like for like comparisons whether you’re in Colombo or New York.
A color description as ‘vB5/6’ for a gemstone should then a little easier to decipher. It refers to a gemstone possessing a violet blue hue with a medium tone and a vivid saturation. The standardization of color removes personal and geographical biases that may come across descriptions such as ‘sky blue’ or ‘ocean blue’ and make the purchase of a gemstone much more objective and hence enjoyable. Now, color can remain a day-long obsession and joy and less of a torment!