My

[psano]

"imperial topaz" ring turned out to really be....

an adalusite!!!



I don't know if you remember I posted this ring online around Christmas. I decided to get it appraised and just got the report back. I kept looking at the report thinking, "What's an adalusite? Is that the same thing as a topaz?"

Duh! Talk about feeling dumb. Oh well, it's still a beautiful stone and appraised pretty well, but I have to admit being a little disappointed to learn that it isn't really a topaz. At least it wasn't something synthetic. I thought some of you might be interested to learn this, fwiw.

I don't see andalusite discussed much, so I guess it must not be very desirable? However, it made me wonder if that's why there seems to be so much more "imperial topaz" online now? Maybe it's being sold as imperial topaz?

Oh well, I guess that means I'll just have another excuse to keep looking for another piece of real imperial topaz jewelery...

 

[MissAva]

Either way, the ring is pretty.

 

[PrecisionGem]

CHEMISTRY Al2SiO5 + Fe
CRYSTALLOGRAPHY Orthorhombic
REFRACTIVE INDEX 1.629 - 1.650
HARDNESS 6.5 - 7.5
SPECIFIC GRAVITY 3.13 - 3.17
CLEAVAGE Distinct one direction
HEAT SENSITIVE No
WEARABILITY* Very Good
SPECIAL CARE INSTRUCTIONS None

ENHANCEMENTS Can be heat treated to improve color. Rarely done.

Andalusite is a strongly pleiochroic gem, which means that is has different colors when viewed from different directions. While it is a strikingly beautiful gem, is largely unknown by the gem buying public.
... It''s trichroic nature, which shows shades of brown, green and reddish brown depending on the orientation of the crystal, can be enhanced by specific orientation and cut. Those cuts with a long axis such as an oval, marquis or emerald cut tend to show one color near the center and a second, usually darker color near the ends. Square and round cuts usually blend the colors into a mosaic.
... Most specimens contain some inclusions, the most common being rutile needles. Brazil is the chief producer, but Sri Lanka, Russia and the US also have deposits. Of course, so does the site of original production, Andalusia, Spain.
... Andalusite is hard and tough enough for most jewelry uses. Poorly cut and polished stones are pretty dull and insipid looking, but a large, clean, well-cut Andalusite is a show stopper!
Value
... Sinkankas places a wholesale value on small, commercial quality faceted stones at around $40 per carat for clean gems with good color. Larger stones and those with custom cuts fetch up to $200 per carat. Federman doesn''t give an exact price range, but suggests that, next to other gemstones one might find in good jewelry, they are "reasonable".

 

[blodthecat]

Gorgeous

blod

 

[valeria101]

He, he...

Well, I am sorry to hear about the misrepresentation, but sure glad to hear the result of the appraisal. The stone looks quite large, and andalusite above a couple of carats is not common at all. Not to mention some that clean and with such nice color to pass as imperial topaz even from a distance! For larger pieces I expect some military green with rusty and yellowish shade - not nearly what you have. Although I suppose that can happen once in a blue moon.

I doubt andalusite could possibly be used as a common 'stand in' for high quality topaz - it is allot more rare!


Way cool! (assuming the appraisal is correct).

I am frankly surprised at the size and quality of the stone... for andalusite. Good for you!

Too bad it didn't carry the right label from the begining

 

[Gemklctr]

Andalusite is sometimes described the poor man''s alexandrite because it''s trichoic nature mimics color change properties. I think it''s a very attractive and desirable gem, and as Ana notes not very common in larger clean stones, so you have something unique and beautiful that you should be proud to wear.

 

[Richard Sherwood]

I'm a little surprised at the ID of the gem given the color shown.

I've never seen an andalusite looking that good. Usually the color is strongly modified with green and brown overtones, with strong dichroism (sometimes pleochroism) evident. Does this stone seem to have some green or brown overtones when viewing it while moving the stone?

Have you talked to the seller about it? There's about a four time (or more) price difference between andalusite and topaz, with topaz being more expensive.

Was the stone inexpensive?

I'm just wondering if the appraiser might have misidentified the stone. The refractive indexes and birefringence are fairly close between andalusite and topaz:

Topaz: 1.627-1.619, plus or minus 0.10, with a birefringence of 0.008.

Andalusite: 1.643-1.634, plus or minus 0.005, with a birefringence of 0.009

When you take into account the plus or minus factor, you could have very close refractive indices:

1.637-1.629 (topaz) versus 1.639-1.629 (andalusite). The two could be easily confused if refractive index were used as the main determining criteria (which is typical).

The only reason I mention it is because (1) the photo does not indicate the typical "look" of andalusite, and (2) usually sellers know what they are selling (unless naive or misrepresenting, of course). With the large price difference between the two species, I would expect most savvy vendors to be sure of what they have.

You might consider a second opinion on that ID. If you don't have anyone local that you're comfortable with, I'm curious enough to do it for you at no charge except for return shipping ($38 fedex overnight, plus $3 per thousand insurance).

 

[moon river]

I read somewhere that Christians would wear andalusite to identify each other when they were being killed for practicing Christianity. There is always an inclusian in each stone in the form of a cross.

 

[Richard M.]

Date: 3/26/2006 3:07:17 PM
Author: moon river
I read somewhere that Christians would wear andalusite to identify each other when they were being killed for practicing Christianity. There is always an inclusian in each stone in the form of a cross.

Well, almost. The story has to do with chiastolite (see image) aka "Cross Stone," which is the opaque variety of andalusite, not the gemmy transparent crystalline kind. The ''cross'' is caused by carbonaceous inclusions.

Richard M.

 

[Richard Sherwood]

Cool. I never knew that.

That's where the fish symbol arose for Christianity, by the way. It was a secret symbol used in the times of Roman persecution.

When a Christian suspected a stranger he met might be a believer, he would draw the one-half curved outline of the secret Christian "fish" symbol on the ground, as if "doodling". If the other person completed the symbol, the first knew the second to be of like mind.

Richard M., have you ever seen an andalusite looking as good as that in Psano's photo?

 

[moon river]

Date: 3/26/2006 6:54:16 PM
Author: Richard Sherwood
Cool. I never knew that.

That''s where the fish symbol arose for Christianity, by the way. It was a secret symbol used in the times of Roman persecution.

When a Christian suspected a stranger he met might be a believer, he would draw the one-half curved outline of the secret Christian ''fish'' symbol on the ground, as if ''doodling''. If the other person completed the symbol, the first knew the second to be of like mind.

Yep. That was the begining of the ''Jesus Fish'' symbol we see on car bumpers today.

 

[Richard Sherwood]

Date: 3/26/2006 3:07:17 PM
Author: moon river
"when they were being killed for practicing Christianity."

They''re still being killed, by the way. All over the world, and particularly in the Muslim countries.

Forgive the off-topic.

 

[moon river]

Date: 3/26/2006 7:03:59 PM
Author: Richard Sherwood

Date: 3/26/2006 3:07:17 PM
Author: moon river
''when they were being killed for practicing Christianity.''

They''re still being killed, by the way. All over the world, and particularly in the Muslim countries.

Forgive the off-topic.

Very true. I''m guilty of not thinking before I speak(type) You''re absoulutely correct. I apologize for my miswording. I hope I didn''t offend anyone.

 

[Richard M.]

Date: 3/26/2006 6:54:16 PM
Author: Richard Sherwood
Richard M., have you ever seen an andalusite looking as good as that in Psano''s photo?

No, my reaction was the same as yours. But you know how it is with images... anything''s possible. The andalusites I''ve seen are generally very dichroic with strong overcasts of brown or green like the image.

Richard M.

 

[Richard M.]

Try again without the # in the image name.

 

[moon river]

That''s closer to the color I''m used to seeing. Usually with a little more orange, but not as ''topaz like'' as psano''s.

I''ll probably be cast out of PS forever for saying this....But I got my ''little education'' of gemstones from watching Jewelry Television.

I was recuperating for months from an injury and couldn''t really sleep at night for the pain and it was all that was on. My loving jewelry like I do, I found it interesting. Never ordered. Just watched and learned.

 

[moon river]

BTW psano, since I seem to have hijacked your thread, I never told you that I''m glad you know what your stone is now. I was lurking then and remember your quest to identify it. You should be honored to have this gemstone. Do a little research on its history. I hope you treasure it.

 

[pricescope]

PrecisionGem,

I'm afraid that the information you posted above about Andalusite is "lifted" from http://www.gemsociety.org/info/gems/Andalusite.htm. Legally and from the standpoint of common courtesy, credit must be given for this exact information written by Barbara Smigel of Artistic Colored Gems.

Fair use of copyrighted materials doesn't allow copying entire content from other sources - only a short quotation with appropriate credits and references to the author and the source of the cited materials.

 

[MINE!!]

Date: 3/26/2006 7:03:59 PM
Author: Richard Sherwood

Date: 3/26/2006 3:07:17 PM

Author: moon river

''when they were being killed for practicing Christianity.''

They''re still being killed, by the way. All over the world, and particularly in the Muslim countries.


Forgive the off-topic.

Thats reall really cool (the stone I mean) I am going to have to find one of those.

Richard, yes they are.. ever read the book by DC Talk? Great Book...

Sorry to hi jack this thread for a moment.

Your ring is beautiful! Sounds as if you got the better deal this way!

 

[valeria101]

Couldn''t do better than posting more pictures of anadalusite (the image search in Google can do as much too), but I am quite curious about your stone - if in person it does look anything like Andalusite. The one picture of the ring posted doesn''t, really. Although I have seen some unusually light anadalusite ... that I could not find any reasonably matches for on a quick search online.

The play of color should be obvious though, no matter how ark or light the stone is. Does yours show any? (reddish and greenish flash as the stone is moved around)

Sure, the RI comes close between the two (topaz and andalusite), but I wonder how could the two be confused at a simple eyeball test

In fact, I wonder if andalusite can be easily confused with anything at all (thinking os ''sunset'' tourmaline, some chrysoberyl with poor color change, brownish zoisite - but none is quite like it, and definitely not topaz).

Still hoping that the ID was right and you have the most beautiful, large andalusite in history.

 

[valeria101]

Richard M., Richard S. & All... there are a couple more pictures of this ring from different angles on the original thread with no trace of pleochroism whatsoever.

Am I seeing things... or is there not a chance that the alternative ID was correct

 

[londonblue]

that''s a very pretty ring!
but it doesn''t look much like andalusite to me in the other photos either.. nor does it look like imperial topaz - i thought imperial was supposed to have more of a pinkish tint to it? maybe more along the lines of precious topaz?

but then what do i know