Sapphirine, interesting reading on wiki about it. This was my first piece I found at Ponderosa, near hanging rock. Where you dig in an old river bed that has all but rotted away over time, a clay/sandy loam! It's hard to describe but washes well and does leave some rust stains on ya. My friend got a yellow one which are rarer than the blue/green ones, I tried rubbing a few down on the wheel hoping to cut a cab. But each one has cracks in them and now look like crap, when they could of been worth something as a specimen. They do have a nice finger print/ feather pattern in the layers.
Iv found lots of Zircons there, hence the name 'Zircon valley' but only a few small pieces of sapphire that might cut. I'm still hopeful as iv only put about a 100 buckets through the HB.