Long Bladed Kyanite Crystals on Quartz

These bladed crystals of kyanite are embedded in quartz. 

The mineral kyanite is well known for its distinctive blue colour. It's a silicate mineral made up of aluminium and silica (aka silicon dioxide).

It often forms long slender crystals which are also known as "blades".

Kyanite has several interesting physical properties one of which is the ability to change colour depending on the angle of light in which it's being viewed.  This characteristic is known as pleochroism.

Minerals that are pleochroic exhibit different colours when viewed from different angles. This is because of its unique crystal structure which allows light to pass through in different directions.

Different wavelengths of light are absorbed in different amounts in different directions which causes various colours to be reflected back to the eye.

This piece has a vitreous lustre so reflects light beautifully.

Due to its fragility this rough kyanite mineral will be very well packaged.  Ideally it should be handled as little as possible.

This impressive piece comes from Minas Gerais in Brazil.  It makes an exceptional display piece.