Danburite

The colorless variety of danburite can be a great alternative to diamond, however it becomes worn much sooner than a diamond, with a hardness rating only a 7 to 7.5 on the hardness scale. Danburite is a brittle and a transparent to translucent stone, a vitreous to greasy luster is a calcium boron silicate mineral with a chemical formula of CaB₂(SiO₄)₂. It has a Mohs hardness of 7 to 7.5 and a specific gravity of 3.0. The mineral has an orthorhombic crystal form. It is usually colourless, like quartz, but can also be either pale yellow or yellowish-brown. This image is by: Danburite