The human eye can see more shades of green than any other color. This makes color the most important characteristic of an emerald as hue and intensity can vary greatly. When it comes to color, the most desirable hue range is from bluish-green to yellowish-green with medium to vivid saturation. The green color of emeralds is determined by the impurities of chromium and/or vanadium, depending on the mine – this means that emeralds from different parts of Colombia, as well as the world, have different shades of color. By looking at color alone, an expert can figure out the location of origin. In determining what gemstone to buy, beauty is truly in the eye of the beholder.
Hue is the basic color of the gem. Some colors are rarer than others. From the hue chart, the only two colors that are relevant when describing emeralds are green and very slightly bluish green. Most Colombian emeralds are bluish green.
Tone is simply the lightness or darkness of the gemstone. According to the GIA tone scale, tone runs from 0 (white or colorless) to 10 (black). Fine emeralds tend to fall between 2 and 8. Note that darker does not mean better. Rich color is the darkest one should look for in emeralds. The finest gemstones are based on taste and generally range from medium, medium rich, to rich color.
Emeralds, a type of beryl, are inherently a fractured material. It takes millions of years for an emerald to form and part of its beauty is the characteristics of its natural fractures and inclusions. Unlike a diamond, there is no official scale that describes an emerald’s clarity, though the degree of flaws varies from one gemstone to another.
The impurities are not just accepted as the norm – they are admired. The imperfections in an emerald are described as le jardín, which is French for “the garden.” An emerald’s jardín presents its own unique fingerprint and is a reminder of its natural formation. Each fracture and inclusion tells a story that took place over millions of years in creating this rare gemstone.
The cut is the overall shape, width, depth, and faceting of an emerald. The cutters strive to maximize the emerald’s color and brilliance within each unique piece. While the end product depends on the specific emerald found in the mine, it also depends on the expertise and vision of the cutter. The shape of the rough, presence of the optimal color, and location of inclusions also contribute to what the final shape of the finished emerald will be. There is no best or most valuable shape of an emerald. Every single cut is with the intention of bringing out the gemstone’s uniqueness and natural beauty.
Emeralds come in all different sizes. Most gemstones are priced solely on their carat weight, but prices for emeralds are mainly based on the color, cut and clarity. Large emeralds are hard to find though, and thus command a higher price. Experts agree that a smaller emerald with brilliant color quality is more valuable than a larger one with poor color quality. Colombian emeralds range from 0.01 carats to over 200 carats in polished gemstone.