Sapphires are generally thought of as blue; however, the range of different colours is extensive. So, sapphire engagement rings can be found in all the colours of the rainbow. Gemmologists use three terms to describe the colour of sapphires and other coloured gemstones. The first of these terms is called the hue. This is basically the actual colour of the gem. The gem might have secondary colours, which can alter a true blue into either a greenish blue or a yellowish orange.
This refers to the colour tone and describes how light or dark the sapphire is. The tone is very important in determining the value of the sapphire. It should not be too dark so that the colour is lost or is inky, or too light so that the colour is not vivid. The most desired sapphires have a medium to a medium-dark tone. With the development of heat treatment in the 1990s, the colours of the stones can be modified, rendering sapphires that are too dark lighter and ones that are too light darker. This has resulted in more sapphires being available on the market, and so sapphire engagement rings are easier to find instead of being a rarity.
The final criterion to asses a sapphire’s worth is termed its saturation, and this refers to how intense the actual colour is. Determining the sapphire’s colour is the saturation modifier; in blue, green and violet sapphires, the modifier is generally grey. In yellow, pink and orange sapphires, the modifier is usually brown. The results of poor colour saturation result in greyish blues, greens and violets; whilst in orange, pink and yellow sapphires, they are described as brownish. Saturation is vital to a sapphire’s value. Despite its hue, if the stone does not have a high saturation, meaning low levels of saturation modifiers, it has a lesser value.
The gemstones’ cut will affect the colour and the brilliance in sapphire engagement rings. Various cuts bring out the brilliance of the sapphire, such as the brilliant cut and the vintage cushion cut. The emerald cut enhances the colour, but the effect is less brilliant.