Commonly known as silk, these decrease the transparency of the gemstone. These needles are almost like birthmarks, that develop naturally in the stone as it forms. This is due to the gem’s crystalline structure.Īn interesting characteristic of a sapphire is that they sometimes contain minor inclusions called rutile needles. Sapphires can display pleochroism: an optical phenomenon that causes the sapphire to display different colors at different angles. Sapphires and rubies are both corundum and structurally identical but they have historically always had their own names. For example, a deep blue sapphire contains titanium and iron, while a pink sapphire contains chromium. The color of a sapphire depends on the element that is most prevalent in the corrundum’s lattice structure.

Sapphires score a 9 on the Mohs mineral hardness scale-a measure of the resistance of materials against scratches of harder materials. A precious gemstone, sapphires belong to the corundum mineral family, and consist of aluminium oxide, iron, titanium, chromium, copper and magnesium.Īs part of the corundum family of minerals, sapphires are an incredibly durable gemstone, ideal for everyday wear.

Sapphire engagement rings