Learning about gemstones

[Camellia]

Hi

I''ve been reading the posts about coloured gemstones and I''m wondering if the experts could pass their opinions on this stone. The details are:

Weight: 22.28 cts
Dimension: 19 x 14 x 9mm
Cut: Step Cut Oval
Clarity: Internaly flawless
Colour: London Blue
Origin: Unknown
Treatment: Probable
Comment
Hand cut in Idar-Oberstein, Germany. Large stone here for a lovely feminine pendant or bold ring.
Does this stone have a window? I''m trying to apply the things I''ve read to the things I see, so please bear with me.

 

[rubydick]

Sorry to be the bearer of bad tidings, but if this was indeed cut in Idar, then there must be a lot of Germans cursing the man who cut this rock.

Yes, it has a window, and if indeed it is blue topaz (you didn't say; it looks like it), it is not probably treated, it is treated

In the words of Burt Bacharach & Hal David, with this one, "walk on by."

 

[Camellia]

Thank you for the feedback. I''m not disappointed because I had no intentions of buying it - I''m just trying to apply the little bit of knowledge I''ve gained from listening to the experts.

To further my knowledge, why do you say it is definitely heat treated - how can you tell?

And yes it is listed as a topaz. It''s also listed as being reduced by 70%. I have definitely taken notice of the advice that you get what you pay for - I''m just trying to identify what that is.

Thanks - I appreciate your comments.

 

[valeria101]

Date: 11/10/2004 10:108 PM
Author: Camellia

To further my knowledge, why do you say it is definitely heat treated - how can you tell?

There is NO blue topaz that has not been irradiated and heated to obtain this color. That stone is a real sorry chap, IMO - it may have looked better with a better cut (color looks nice) but like this ? No go. It could be free, let alone "70% discount" from I don't know what

At cents per carat for the rough, why would anyone cut anything but the nicest things out of blue topaz ?

Speaking blue topaz... creativegem.com seems to take special pride in marketing a dozen or so types of it. Worth a look, if only for the nearly exhaustive list of trade names used to sell blue topaz. And These Guys definitely have an exhaustive low-down on where and how topaz comes from (approximate translation, but great info nevertheless).

These being said, you may find "blue topaz" without enhancement. It's dirt cheap and very, very faintly colored - so much so that it is hard to show that tint other than in person (as opposed to photos). In theory exceptions to this rule exist, but I have not touched naturally colored blue topaz of decent color for more than a decade. If anything, you may find blue tinged crystals uncut sold as specimens. This last comment is just about as relevant as debating the shape of dragon scales - there are no dragons

I wish I knew what the right way to learn gemstone facts is - but I really do not.

Richard Wise's book is a nice start - long list of gem types, fast read, what not. Online, I love the pages on Palagems - there is allot of info in a very tight place there. There are purely academic sources as well, with only faint if any connection to the trade: lots of gemology course around, including THIS.

Shopping around helps, but it may take allot of it to learn what to look for. And it can get expensive too, unfortunately

 

[Camellia]

Thanks for that. I appreciate all the expert advice. Now, to keep learning.