Sapphire Cut Stone, Round, 3.8 to 4mm

The name Sapphire used to be applied for various stones, this was changed in the early 1800s and made that corundums of gemstone quality of all colours except red are called Sapphires but are titled via their description. For example, Green Sapphire and Blue Sapphires. In artificial light, the blue sapphires can appear to be ink-coloured or black-blue but in natural light, they are a violet light blue. 

Shape: Round

Size: 3.8 to 4mm

Weight: 0.07grams

Colour: Blue glassy

Moh's hardness: 9

Density: 3.95 - 4.03

Cleavage: None

Refractive index: 1.762 - 1.788

Dispersion: 0.018 (0.011)