The hue of the gemstone refers to the color itself. For example, the ruby is most known for its pink and red hues, and emeralds are best known for their greenish and yellowish hues. In most cases, gemstones have a primary and a secondary hue, but when weighing the value of the gemstone’s color, experts often search for stones that are as free from secondary colors as possible. In general, the most valuable gemstones exhibit a pure color and only slight hues of others. Exceptions include the opal, which is a unique gemstone that increases in value when there are more visible colors throughout.
The tone of a gemstone’s color refers to the depth of the color, from dark to light. When categorizing a gemstone’s tone, experts use the following terms to describe the range in its opacity: light, medium-light, medium, medium dark and dark. To evaluate the value of a gemstone based on its tone, we recommend holding it under a table or away from any direct light. This technique allows you to more easily determine the tone of a gemstone, since a brighter stone will still have life and brilliance, even when light isn’t directly shining on it.
Gemstone clarity grades identified by the GIA indicate the size and visibility of the inclusions in a gem.
Inclusions are very, very small.
Inclusions are very small.
Indicate a gem with small inclusions—SI1 gemstones have smaller inclusions than SI2 gemstones.
Indicate a gem with inclusions—the higher the number (1, 2, or 3,) the more inclusions the stone has.
Each clarity grade means something different for each gemstone type. For example, for a Type 1 gemstone, like aquamarine, a grade of VS means the stone has tiny inclusions that are fairly easy to see under 10x magnification, but these gemstones are usually eye-clean. But for a Type 3 gemstone, like an emerald, a VS grade means it has obvious inclusions at 10x magnification, which may be eye-visible. The right an gemstone cut can help reduce the appearance of inclusions The most important thing to consider when purchasing any gemstone is how much you like it. If you fall in love with an emerald that’s heavily included and has a mossy look, known as “jardin,” which is French for garden, then choose that emerald over a cleaner one that’s more “valuable,” but may not be the gem that captures your attention.