Something Different Feldspar?

[fossickeract]

     Often on our fossicking trips to Grabben Gullen while looking for sapphires and zircons we find a clear greyish mineral, its light and often flawed but get occasional good bit. It has a cleavage 90* hardness about 6.5 and SG suggests feldspar  . Colour appears grey, hint of pale blue, pale orange and brown depending on axis viewed so I had a go with a deep EZ Barion emerald cut to increase colour. Results were a surprise a deep chocolate brown with orange flash and I suspect its similar to sunstone found in the US. Whatever it is I think its worth picking up and might try a bit in a shallower round brillant. Two photos showing back lit the pale material I start with and the finished gem will go up when I get it to work.
                                                                                                    Ted

Images added:

[Findem]

Interesting, Ted. I've been wondering about the cabbing prospects of the pink orthoclase felspar from around here. Quite apart from the strong cleavage, there is the added problem of finding really fresh specimens. When I do my Hartley granite blog soon, I'll include some pics.

[Fullerton]

I saw the pics of the faceted stone - great stuff and well done. Would certainly be looking for more! 

[Wwoofa]

Looks really nice Ted 

[Lefty]

It does look nice, especially the second photo. But what exactly is the stuff? Is it related to labradorite?

[steveo]

It does look very nice.

[fossickeract]

 Thanks for the comments. Yes think so Lefty in the feldspar family first cousin to the honey coloured labradorite found round Springsure perhaps. Going to get refractive index measurement to see which one but told its Calcium rich due to dark colour probably Anorthite or Bytownite                            Ted

[Blash]

its a great looking stone whatever it is
a couple of ways to tell from my experience. a lot of the more gemmy feldspars ive seen have some chatoyancy so that could help and if its a ca rich feldspar its likely a plagioclase feldspar so in its rough form its crystalisation pattern has twinning which appears sort of like striations that run parallel to each other, but yea thats only if you have some rough, these should be visible through a 10x-20x hand lens or some are visible with the naked eye.
hope this helps