Help me identify this 4" diameter sphere - fibrolite?

[bluelotus]

Hello all,
This is my first time posting in the colored stones section.
I just returned from a Saturday morning flea market where I purchased this lustrous beauty. It is a deep lavender and appears to be some form of cats eye? Is this rare in this size? Does this appear to be natural? With the exception of a small bruise the finish is perfect and glass-like. I was so intrigued by the optics and size and simply couldn't resist!

 

[Marlow]

Looks like a Sillimanite Cat eye ( Fibrolite is a Synomym for Sillimanite).

There was a larger found of this variety - they sold hundreds of them. Looks similar. A beautiful material.

Sillimanite has the same formular like Kyanite and Andalusite.

 

[bluelotus]

Would this be natural or synthetic?

 

[Marlow]

Natural - untreated - try to find some infos...

 

[bluelotus]

Is this rare or especially valuable at this size?

 

[LoversKites]

Closest comparison I found:
http://www.thegemtrader.com/Oct14CESilliPage.htm

Yours is huge in diameter, I have no idea about it's worth at that size.

 

[Marlow]

Do you have a picture of the backside? Could be a glass imitation too.

They sold many of them - no information about price per carat at the moment.

 

[bluelotus]

The whole thing is finished the same all the way around. . . it is a perfect sphere. Perhaps it is just glass at this size. . .

 

[bluelotus]

Looking at it again, I don't think it is glass. Seems too dense and heavy.

 

[pregcurious]

Don't know anything about the stone, but just wanted to say that I love the ring in your avatar.

 

[bluelotus]

Hi pregcurious,
Thanks for the compliment. I have a couple of threads on the ring and the restoration of the Calibre cut side stones.
The stone is an early round brilliant with what appears to be FIC proportions.