There’s a lot to know when it comes to colored gemstones. Many factors go into assessing their beauty and value. There are myriad variations in colored gemstones and those all need to be analyzed to profile the gem. Everything from color and clarity to size and where the gem is from all impact the price of the stone. Ultimately, you’ll buy what you really love, but it’s always good to know what you’re buying, so we’ve put together three easy tips for evaluating colored gemstones.
Color
Obviously, the first thing that you will be looking at is the color, usually referred to as the hue by gemological laboratories. When you look at color, it’s natural to be attracted to a shade that you love, but that is only one aspect. Really look closely at the stone. Do you see a secondary color in the stone? It’s very rare for a gemstone to be a pure color. In an emerald, you may have a blue or yellow secondary color, that modifies the main hue, in a ruby you may have pink, orange, purple or brown modifiers. Some modifying, or secondary colors, can add value to the stone, such as pink in a ruby, while brown in a ruby would be less desirable. Generally speaking, gray and brown modifiers are secondary colors that may make the gem less attractive.
Color Tone and Saturation
Next, you’ll want to look at the tone of the gem, which refers to the lightness or darkness of the hue. If the tone is weak, or too dark, which means you can’t see the beauty of the color, then it detracts from the value of the gem. You should also look at saturation, which is a measure of the amount of color, how intense is the hue of the stone? Light color saturation is what we know as pastel, where as a stone with a higher saturation could be described as vivid.
Clarity
Clarity references the inclusions and surface blemishes on a stone. You’ll want a gem that has the least amount of inclusions and blemishes. The fewer blemishes and inclusions a stone has the better the quality the gem. Almost every colored gemstone will have inclusions of some sort and almost all colored gemstones are enhanced in some way to improve color or clarity. It is extremely rare to find a colored gemstone that naturally has no inclusions, when those stones are found they are very expensive. The types of inclusions and the amount will depend upon the gem. For example emeralds almost always have numerous inclusions, it is part of their natural beauty. In the case of Kashmir sapphires, a very specific type of inclusion helps to identify the gems as being from that area. While you want a stone that is as pure as possible, inclusions can sometimes provide valuable information about a stone. Remember the perfection of a colored gemstone is to some extent its imperfections. Natural gemstones have inclusions, they are often invisible to the naked eye and are part of the charm of the gem.
Size
Size is generally the carat weight of a gemstone. The term carat is derived from the word “carob”. Historically carob seeds, with their fairly consistent weight, were used to measure the size of a gem. As weight methods improved, a carat was defined as one-fifth of a gram — meaning that there are five carats in a gram. There is more to size than weight. All gemstones have their own density which will make a difference in the size of the gem. A denser stone, such as a ruby or sapphire cut to the same shape will look smaller than a diamond of the same carat weight in the same shape.
Ultimately, you should buy the gemstone that you really love, just keep in mind the factors that add to its beauty and value when you do make your purchase. Buy the best jewel that you can afford and wear it joyfully.
Top of page: Art Deco 2.85-carat emerald, old European cut diamonds and platinum ring, accompanied by an AGL report stating that the emerald is of Colombian origin with minor traditional clarity enhancement.
Burma ruby 0.89-carats, diamond and platinum ring; Cushion cut 6.74-carat blue sapphire, diamond and platinum ring; Heated 6.16-carat blue sapphire, diamond and platinum ring, accompanied by a C. Dunaigre report stating that the sapphire is of Sri Lankan origin with indications of heat; Colombian emerald 4.50-carats, diamond and 14-karat white gold ring; Mozambique ruby 5.29-carats, diamond and platinum ring.
Authored by Amber Michelle