FMF - Friends of Minerals Forum, discussion and message board

[chris]

Hi Jim,

Good news. Looking forward the next developments...

Thanks.

Christophe

[Tony H Gill]

Hi Folks

Jim - I dont want to take over your story board but hope you dont mind me putting the feelers out in this thread as its a very similar problem to yours but with no interesting evidence! This thread has spurred me to question the validity of a locality for a specimen I own - we discussed this in private.

I tend to agree with you and also think my specimen may be a urals topaz, the reason I ask is that it looks fairly similar to yours, so I would like to see what the thoughts are of everyone else? Apologies for the low quality photo.

https://www.mindat.org/photo-150143.html
(link normalized by Jordi)

Regards

Tony

[keldjarn]

Hi Tony,

From the looks of your very nice blue topaz crystal I would have no problems accepting Virgim de Lapa as the locality. A pragmatic point of view would also be that a true blue topaz of that quality from the Urals would probably cost more than one from Virgim de Lapa. So there would be no economic incentive for a deception as in the case of the "Japanese" blue topaz. But in most cases with common minerals like topaz it is very difficult to tell the locality of single crystals by sight only. If you have labels from the 70'ies or later saying Virgim de Lapa, I would stick to that.

Knut

[lluis]

Agreed with Knut.

By the way, opinions about blue Virgen da Lapa topases?
I heard that perhaps irradiated, but that is no more than hearsay...Just extremely curious

Lluís

[Jim]

Not that I'm an expert, but Tony's crystal doesn't look like any of the fine blue topazes that I've seen from Virgem da Lapa. It looks more Russian to my eye.

[John S. White]

I have to disagree quite strenuously with keldjarn, this topaz looks Russian to me. In my experience with Brazilian topazes they tend to have steep chisellike domes on the termination, not flat pinacoids like this one. In this respect they resemble those from the St. Anne's mine, Zimbabwe. Yes, it is also true that many of the Brazilian topazes have been treated, but not all of them. Some of the best came from the Xanda mine, near Virgem da Lapa. The Russian blues are the ones with flat pinacoids.

[Les Presmyk]

I agree with John. When Virgem de Lapa was in its heyday, Jack Lowell was importing a number of the best specimens from there. I was able to see a lot of what he brought into the country and the topaz crystals were as John has described with chisel terminations and sides containing multiple faces.

[Tony H Gill]

Wow guys, so the consensus so far seems to be that its a Russian specimen! I must admit I have a fair number of topaz crystals and I had some gut ''feel'' that it may not be Brazilian but I went with what I was told...interesting story to add to yours Jim!!? Anyway off for the weekend look forward to any more on this thread, thanks to everyone so far and thanks Jim for letting me dive in part way through your thread!

Tony

[keldjarn]

As stated in my post it is in most cases impossible to make accurate judgements about the locality of single crystals of common minerals like topaz visually. I agree that most Brazilian topazes have more chissel-shaped termination - and this is especially the case with the larger crystals from i.e. Virgim de Lapa and Mimoso do Sul. A couple of years ago I sorted through dozens of flats of single, blue topaz crystals from the Limoeiro mine and even if most of them had the chisseled termination, there were also crystals terminated by a pronounced pinacoid. If you look at pictures posted i.e. in Mindat of topaz crystals said to come from Brazil, you will find many also with pronounced pinacoids including a large blue one posted by Rob Lavinsky and said to come from the Xanda mine ( pic. 74779) and a smaller blue one posted by John Betts just said to come from Minas Gerais.Tony Hill has even posted a picture of a 3 cm crystal from Mimoso do Sul which unlike most crystals I have seen from there is blue with a large pinacoid.
I do not disagree with John and others stating that the small, blue topaz crystal in question could also come from the Urals or i.e. St.Annes mine. If that is what the label said, I would have no problems accepting also that. But since you also occasionally see large pinacoidal termination on smaller blue topaz crystals from Brazil, I would not personally change a label from Brazil to the Urals just because such crystal habits are more common there. But if I had ancountered the crystal in an old European collection with no label, I would absolutely have guessed the Urals as the locality. The moral is: take good care of labels and other documents showing the origin of a specimen and if possible pastye a small label with locality information on the specimen itself.

[John S. White]

While we are at it, perhaps we can arrive at a consensus with respect to the spelling of the locality in Brazil. All of my references (at least those that I trust) spell it Virgem da Lapa, but most of the contributors to this thread appear to prefer Virgim da Lapa. In any case I feel we should take this opportunity to try to agree on the spelling so that readers of this thread can make sure their labels are correct.

[mmauthner]

Quite right, John. The correct spelling of the locality, in Portuguese (I am not fluent in Portuguese, but every map/geographical reference I have, indicates this), is indeed "Virgem da Lapa". Other versions are impositions of or incomplete translations to other languages (i.e. Virgen, Virgim).

As for the crystal, I also agree that it has more of a Russian appearance than those from Virgem da Lapa; however, Mimoso do Sul, is also a candidate, though if memory serves correctly the smaller Mimoso crystals did not have such deep a color and larger Mimoso crystals (as the on im my photo) tended to be color zoned. I favor the Russian attribution.

Cheers,
Mark

[keldjarn]

Sorry for the spelling error, we can all agree that Virgem da Lapa is the correct locality name. But the main issue remains unclear for me. The first post by Tony indicated that the topaz in question had locality information stating Virgem da Lapa and the question seemed to be if this would be so unlikely that it would be correct to guess the Urals as the right origin. Based on other photos of Brazilian topazes also with large pinacoids and my own observations I would not be very happy with i.e. a dealer changing label informations based on such guesswork - especially if that would make the specimen more desireable and expensive...
If on the other hand the crystal had no locality atributed to it and especially if it could originate with an older European collection, I would also guess th Urals.

[GneissWare]

The point raised earlier by Knut seems quite relevant. That is, crystals from the Urals command higher prices than those from Brazil. Thus, relabeling a specimen from the Urals as coming from Brazil would make little sense. The alternative is that the specimen is from an old collection and was without a label, and the locality was guessed to be from Brazil.

My thoughts are to accept a labeled locality as true, unless I can conclusively prove it false. In this case, crystal habit is not dispositive for determining an error in the locality.

If this were my crystal, I would take it to someone like Luis Menenez who has seen most every rock that has come out of Brazil.

My 2 cents.

[lluis]

Good afternoon

I understood same as Knut, and I saw in Mindat same as Knut.
And I agree with his reasoning.
I thought more in a brasilian one because I have seen more gem ones from Brasil that from Mursinska.
But, unfortunately stones does not speak, so..... :-(

On the other hand, even old collections not ever have the right labelling.
I own a pyrope (analyzed), that its previous labels state:
Oriental Hyacint (Ruby)
Later was relabeled as zircon....(before my birth...)
Some much more years later revealed to be a pyrope.
And it was from a very important collection, from a very knowledgeable collector.

With best wishes

Lluís

[Tony H Gill]

Hi again all,

Thanks for the increased info. With regard to my specimen in question, this was purchased about 2 years ago from an internet dealer who claimed it to be from Brazil. Unfortunately it came with no labels (a lesson learnt - however from the pictures it still looked too good to miss!). Since this time, I have kept a closer eye on this particular mineral dealer for any other good specimens and have noticed from time to time that they have posted other specimens with locality mistakes. I left my specimen as is never really giving it a second thought, assuming all was ok until I happened across this thread which made me take a closer look at it. Thinking about it, It almost exactly reflects another I own, that I know for certain is from the Urals, in both colour and form : https://www.mindat.org/photo-171742.html particularly the crystal faces to the left and right of the pinacoid. It has no resemblance to another specimen from VIrgem in my collection (chisel termination) https://www.mindat.org/photo-150136.html , it is also true I have a relatively similar specimen from Mimoso, https://www.mindat.org/photo-134334.html (links normalized by Jordi) but it has a two step (dont know the terminology) to the front of the pinacoid which is not similar to the other 'Ural' crystals. I realise my response is not 100% proof but I have scoured magazines, internet sources etc etc to hunt down topaz specimens and always thought the specimen seemed 'a little too perfect' for a Brazilian topaz which I thought was a great thing to own in its own right! Does anyone have the details of Luis Menenez so he could take a look at this thread?

Many Thanks
Tony