Diamonds are the classic symbol of strong, enduring love, but many couples also choose sapphires as engagement rings to celebrate their romantic love and commitment. Largely due to their durability, blue sapphires are popular for engagement rings, because they symbolize constancy, reliability, and loyalty. Blue sapphires are also popular wedding anniversary gifts.
Natural sapphires are cherished for their wonderful uniqueness. Natural fancy sapphires come in a rainbow of glorious colours: yellow, green, orange, brown, pink, lavenders and purples, and bluish green. As with diamonds, the cost of a natural sapphire depends on its 4C profile—colour, clarity, carat weight, and cut—as well as country of origin. The largest natural sapphire deposits are found in Thailand, Sri Lanka, Madagascar, East Africa, and Eastern Australia.
Different varieties of corundum are distinguished by colour or hue, saturation, tone, clarity, internal characteristics, and optical phenomena. Saturation refers to how vivid or strong the colour is or colour purity—the degree of absence of brown or gray hues. The most valuable sapphires exhibit a near-pure primary colour and only slight other hues. Tone refers to the different shades in the gemstone and is described as “light,” “medium light,” “medium,” “medium dark,” and “dark.” Tone indicates depth of colour and ranges from colourless to black. Clarity and cut are key factors in fancy-coloured pastel sapphires. Naturally, inclusions are more noticeable in lighter stones, and the cut should reflect light evenly across the face of the stone to enhance liveliness and brilliance.
The star-like phenomenon in blue star sapphires is called an asterism. It results from intersecting needle-like inclusions that render a six-pronged, star-like pattern under a focused light source. The value of a blue star sapphire depends on carat weight as well as the body colour, visibility, and intensity of the asterism.