Tourmaline aficionados lend me your eyes !!

[LD]

I'm going to say what I think many are concerned about if you don't mind?

1. Your jeweller didn't do the tests in front of you SO it's impossible to validate what he did and how?
2. You (presumably) don't know how skilled he is with coloured gemstones.
3. A simple RI test could be done right in front of you.
4. He's saying this has a cat's eye in the white part? Well, there's absolutely no evidence of one in your photos. I'm not saying he's right or wrong BUT .............
5. He said that to be sure you could send it to a lab and he'll discuss the findings with you? That suggests to me he's not sure. IF he was sure he'd tell you categorically what it is and why he thought that ie the RI, the density etc.

Look at the second photo in this link - don't you think it looks remarkably like yours?

http://www.gemselect.com/other-info/synthetic-quartz.php

If you tell us what country you're in, we can tell you what lab you could use - there are good reputable labs and then those that are far less reliable. Shipping shouldn't be a problem and if it's important to you what this is, I'd do it. That way at least you know for certain. Unfortunately I don't think you do at the moment.

I'm keeping my fingers crossed it is a Tourmaline.

 

[chrono]

To do his testing, I do not know why the jeweller had to take the stone into a back room. It is very easy to do the refractive index testing right in front of you as the refractometer is a small pocket-sized device. The microscope is usually in the front room too and all the jewellers I've dealt with allowed me to view it as well. You mentioned that you are in a small town, so this is another concern that the jeweller may not be well versed with coloured gemstones. I find his claim of a cat's eye on the white portion to be a far-stretch. Not being able to tell you specifics is another way of informing you that he's not sure, hence the follow-up advice for you to send it off to a lab.

Mailing of stones within the US is very safe, especially when using registered mail with tracking and signature receipt. I'm another in rooting for a tourmaline result!

One of the many examples of similar such stones all over the www: hydrothermal aka synthetic bicolour purple and white quartz.
http://www.amazon.com/Emerald-Purple-Bicolor-Ametrine-Gemstone/dp/B009C2QG1Y