This is one of my favourite types of sapphires, with a blue Crescent on one Edge, reflecting across to the other side, creating a 'butterfly wing like' effect.
The blue and yellow colour zones mix in different ways, depending on the angle viewed from, and will create a little green/teal colour here and there where the colour zones interact.
6.0mm diam x 4.0mm depth.
No fractures and unheated.
There is some very fine silk in the Blue colour Zone.
In the late 60s and early 70s there was a gentleman who lived on the Central Queensland gemfields and ran a one man operation.
Using a tractor with a bucket on the front, the man unearthed the gems, they were then put through an agitator, hand sorted and then faceted.