Star Sapphire?

[JBK]

Hi All, if I was to cab this sapphire along the c-axis to see if I can get the star showing, would you start with the smaller or larger plane? Thanks Joe

[MakkyBrown]

I wish you best of luck, I have a good track record of not finding stars 

[JBK]

Thanks MB, I know what to expect then😊

[swirly]

some one once told me to put a drop of baby oil on the c axis then a bright flash iite should show a small star if there is one there.good luck

[JBK]

Thanks swirly, will try

[Faceting Frank]

Don't want to look stupid, but what is the C axis?

[JBK]

I only just read about it last week.

[JBK]

Touched it with #600 grit but can’t see anything promising

[RHS]

You won't see a star on a flat. Put a drop of high viscous honey or similar on the stone. Have it domed. You may then see a star. All the best!

[JBK]

Ok thanks for the advice, I will try that

[Manficat]

I've never really seen these stones before. So are they a bit of corundum with a star on them? If so, how do you know that there is a star if you can't see it? Although you haven't found the star yet, the rock still looks very interesting! Did you find it in a creekbed?

[JBK]

Yes Mandicat, found GG creek gravel. Have few specimens ( not faceting material) that I’m not too sure what to do with it , hence looking to see if there is any signs of star.

[Manficat]

Interesting! Good luck

[Bucket]

I've never really seen these stones before. So are they a bit of corundum with a star on them? If so, how do you know that there is a star if you can't see it? Although you haven't found the star yet, the rock still looks very interesting! Did you find it in a creekbed?

The star is a resultof light reflecting back off rutile inclusions in the stone. It usually only is visible from one direction and I'm not sure on what axis it's visible as like you, I haven't had a lot to do with star sapphires. I do know that the black or dark blue with the gold star looks brilliant and that the star colour can vary from silvery white to gold. I also know that if you cut it on the wrong axis, the star won't show up, it will just look like a silvery/gold sheen.