FMF - Friends of Minerals Forum, discussion and message board

[Scott LaBorde]

Hello?

[Jordi Fabre]

Scott,

Everybody is in Tucson now, extremely busy and with very bad Internet connections. Please be patient, people will be back in a few days....

Jordi

[Scott LaBorde]

Of course, I should have known! Thanks Jordi.

[John S. White]

This does not appear to be a scepter. It has no stem.

[Amir Akhavan]

@Scott
It certainly looks like a scepter - just the stem is missing - oops ;-)
I apparently have a much lower threshold than John when it comes to calling something a scepter.

I can see why you ask that question.
The surface of the prism faces looks like that of a skeleton/scepter, so the crystal might have assumed a "scepter mode of growth".
Just cut the crystal into two halves to check if the stem has been overgrown completely - just kidding.

You could X-ray it and might see a hint of something.
I've seen X-ray images of crystals, but I do not know how to do it properly and if it also works for complete crystals instead of slices.

Or maybe you are referring to the steps in the rhombohedral faces.
That alone would not turn it into a (reversed) scepter for me.

Amir

[Scott LaBorde]

Thank you John and Amir. Would you have any suggestions on which habit or combination of habits to call this crystal?

[Amir Akhavan]

The habit is simply "normal" (or "Maderan" if you want to show off with an odd term).

The fact that it has steps etc. doesn't justify giving it a special name.
But if you wish you are free to give it any name.
If I see a crystal like this I sometimes say they have "scepter habit" or "scepter-like habit" but I'm stretching the term "habit" quite a bit when I do that to describe the sum of normal habit, types of faces and surface patterns. Then I usually get corrected by others who point out my sloppiness (didn't you do so some time ago?).

Amir

[John S. White]

A problem is that even though you provided a number of fine photos, you neglected to include one of the base. If this is a true scepter with the stem broken off then I would be inclined to label it "scepterlike" as suggested by Amir. On the other hand it is not necessary to label all of the habits of one's quartz crystals unless they clearly are a good illustration of a particular type.

Hope to be leaving Tucson tomorrow. Our leader Jordi had his flight to Atlanta cancelled so he is facing a long flight home today via Minneapolis. Good luck Jordi!

[keldjarn]

I have mostly seen true scepters with a larger crystal in eptaxial growth on top of a more narrow stem of the same mineral in varieties of Quartz. But I have a unique 15 cm specimen from Virgem da Lapa with such a true sceptergrowth of blue Topaz. I have tried to enclose a picture of the specimen.
Knut

[Tsinidis Tasos]

Just a small photo contribution from me on the smoky-amethyst scepters from the alpine type quartz veins of Kato Nevrokopi basin,Drama prefecture in Greece.

[Tsinidis Tasos]

Also the only four known (and two colored) reverse scepter quartz crystals found in the same location (Kato Nevrokopi basin).

[Scott LaBorde]

Tsinidis, very nice specimens. I especially like the first photo with the smokey amethyst. Thanks for sharing.

Scott

[Terry Burtzlaff]

Here is one of my favorites - a Quartz scepter from Herkimer County, New York. While I don't know of any reverse scepters occuring with these, skeletal Quartz is fairly common in the pockets. The "cap" on some scepters is so transparent that the dark stem host crystal is clearly visible within.

[Luiz Menezes]

Hi Knut:

Your topaz scepter is very impressive but I think it is likely not from Virgem da Lapa; all crystals I have seen from the famous Xanda and Limoeiro mines show visible etching patterns on 2 opposite prism edges, and your specimen shows no etching. It also shows a darker blue color than the normal color from the Virgem da Lapa topaz.

When I return to Brazil next week I will try to contact Álvaro Lúcio to show him the photo and ask him about his opinion; during the time both mines were producing strong (1978 to 1981) Álvaro was very active on the mineral market, and I was still working at the Jacupiranga mine, so he has much more experience than I have with Virgem da Lapa topaz.

Regards

Luiz

[keldjarn]

Hi Luiz,

Thanks for your comment and for wanting to verify or correct the locality info. It is one of the few specimens in my collection where I have not been able to locate the original label. I bought it at the Executive Inn (main building, second floor) show in Tucson 15 years ago from a Brazilian Dealer (probably from some younger dealers working for Àlvaro ?). It was said to be an older specimen from the Virgem da Lapa area. The Topaz is somewhat lighter in colour in artificiall light and has a few bottlegreen embedded Tourmalines.
I fully agree with your comment that the Topaz do not resemble the more common ones from Xanda or Limoeiro which are often partly etched. But coming from pocket-pegmatites the condition of one pocket or pegmatite may be different from another also in relation to hydrothermal etching of the crystals. If you can provide data to support another possible locality, I will be very grateful, but until then I will stick to the information provided by the Brazilian dealer.
Knut