The beautiful colour of a gemstone is its most defining characteristic, and many jewellers consider it to be the most important evaluation criterion. When deciding upon gemstone colour, examine hue, tone, and saturation.
The most valuable gemstones are those that exhibit a pure colour and only "slight" hues of other colours in addition to their primary colour, as all Blue Nile gemstones do. For example, Blue Nile sapphires range in hue from "slightly purplish-blue" to "slightly greenish-blue," pink sapphires always range from "pink" to "slightly purplish-pink," and rubies range from "slightly orangish-red" to "slightly purplish-red". With the exception of opals, variation in a gemstone's hue will be called out in the gemstone details on the product detail page.
Tone represents the depth of colour, ranging from colourless to black. Gemstone tone is described as "light," "medium-light," "medium," "medium-dark," and "dark." Blue Nile offers gemstones with the most sought-after tones that fall within the medium-light to medium-dark range. For all of our gemstone jewellery, you'll find any tone variations are called out in the gemstone details.
Saturation, or colour purity, refers to the degree to which the gem is free from brown or grey hues. The most desirable gemstones, which show little grey or brown, are often described as having "vivid" or "strong" colour saturation. Generally, the levels of colour saturation will not be called out in the product details because the gemstones in our jewellery are hand-selected for their vivid colours.