FMF - Friends of Minerals Forum, discussion and message board

[John S. White]

This is a "sleeper" amethyst that I bought at this past Tucson Show. It was originally very large but I had it trimmed to a smaller size, now about 10 cm across. The "buttons" are calcite, but I have no idea what caused them to form this way. It is from Rio Grande do Sul, Brazil.

[John S. White]

This is a cute little quartz from Leshan, Sichuan, China, sorry about the less that elegant photo. It is 7.5 cm in length. I was really pleased to find this jewel in a flat of more or less ordinary quartz crystals. For those of you who like to speculate on how scepters form, this is a real challenge. I call these "head scratchers" because they are difficult to understand, and I particularly like "head scratchers." You will find many of them in my collection.

[John S. White]

Among my many quartz specimens you will find many examples of crystals with interesting inclusions, such as this one. This is a portion of a crystal from Amatitlan, Guerrero, Mexico, and it has these wonderful oriented empty holes, which mineralogists often refer to as negative crystals. The entire crystal is 4 cm long. The photo was taken by Russell Feather of the Smithsonian Institution.

[lluis]

Good afternoon, Mr. Sampson-White/List

Thanks a lot for sharing!
Sorry for delay in answering but I am an extremely slow typer.... :-(

WOW! I whish I got your skills to trim the ametist! The piece you produced is really beautifull, and I could not imagine it seeing the big one you.
Nature produces wonderful pieces, but man also helps to display them in full beauty!

The multi sceptered quartz is indeed very curious. As you said, a head scratcher!
Nice! And my congratulations for finding that! (I am very bad at shows; too many people and too many pieces to choose from in a so small time....

But my prefered is still your curved quartz!
I still remember the talking we all had in Forum about the genesis of such curvature.

And I still have the sweet flavour of your Mont St. Hilaire rhodo....!
If anytime you decide to look for another home for her, you know :-)!

May I dare to ask you to share more pieces?

With best wishes

Lluís

P.D.: not to mention the heliodore! Impressive!!!!!!!!! I also like cut stones.... :-) and collect, in the rare cases in which are sold wilth detailed location (not Nigeria alsone, as example...)
No one is perfect, but, who wants to be Noone? :-)

[John S. White]

Thank you Lluis for your kind words. I really enjoy showing my collection to visitors, so the Forum offers a new way for me to share it with more people. That is part of what makes collecting so rewarding.

This piece is a section of polished quartz from Rio Grande do Norte, Brazil. Because it is polished Jordi would hate it. The polished surface is 5 by 3 cm. Within it one can see a zone of white bladed cookeite crystals over which is a zone of space-ship-shaped flat apatite crystals that are blue with white centers. I wall attach a couple of photos. Those photos were all by Russell Feather.

[lluis]

Dear Mr. Sampson-White

Indeed interesting!
I normally do not like polished surfaces, but if it the only way to see inside a crystal, what could I do? (not to say cut gems..... At the end, they are cut from chunks of material, the rest of crystal being discarded because it is not so gemmy....)

Very nice photos and very nice specimen. The last I would think to find inside a quartz!

Thanks again for sharing!

With best wishes

Lluís

P.D.: I live really far from USA. If not, I fear that you will have a recurrent visitor to your home (well, collection :-) )
If you come to Spain, you are invited, of course.
Not a bad cook.... :-)
And my wife, a far better cicerone than I

[Cesar M. Salvan]

I think that Internet is a good tool: permit to share things that, without our technology, usually remain hidden to our eyes, in the place where they are deposited.

Truly connoisseurs as well as professionals in the field that share scientific work with collecting (usually a rare combination, at least here...) are usually reluctant to share their "personal mineralogical treasures" with the community, I guess by a variety of reasons. But, where people of great stature, as J.S. White, take the time necessary to share his specimens, it could be an inspiration for all the collectors.

For example, I am not a quartz collector, but your specimens goes beyond. I am particularly impressed by the apatite crystals in quartz you showed in last post. The use of polished sections or thin sections is not usually the focus of mineral collectors, but I think is just another way of specimen preparation, may be deeper than simple stacking in perky boxes or so, but is very useful to appreciate certain species or interesting features. As always, as deeper your knowledge, stronger your capacity to savor things that usually are out of reach of less educated rockhounds. when we see collections of very educated individuals, we quickly see that price or size of specimens is not determinant. On the contrary, oddities, personal history and scientific interest is the driving force. Please, Mr. White, correct me if I am wrong.

And this is why we must acknowledge the effort to share from John S. White.

[Jordi Fabre]

I split this topic, creating a new thread named: "Too much of the same thing" ( https://www.mineral-forum.com/message-board/viewtopic.php?p=5465#5465 )

As the photo of this Chinese Quartz was related with the other topic I copied it below, in order to keep coherent this topic of John S. White collection.

Jordi

[John S. White]

Two more of my included quartzes. Sorry Jordi, they are polished, otherwise we would not be able to see the inclusions. I do not know what the inclusions are. They both are from Minas Gerais, Brazil, and the photos are by Jeff Scovil.

The first one is about 8 cm tall and the other is 6 cm.

[John S. White]

This is probably the largest specimen in my collection, it measures 15 cm across and is from Rio Grande do Sul, Brazil. I acquired this piece because of the cristobalite incusions, which I first became aware of when I was at the Smithsonian and X-rayed one of these. In the close-up you will notice that the cristobalites are elongated and tubular looking.

[parfaitelumiere]

second quartz is really a killer specimen,like a fireworks...;)

[Carles Millan]

Hi John!

I must congratulate you for the excellent article "John S. White, Jr. and his Single Crystal Collection", by Thomas P. Moore, published in The Mineralogical Record, #40/3, about your professional life and minerals collection. I've got the issue this very afternoon and am right now reading the article carefully.

I encourage you to post more pictures of your single crystals here at the FMF for all of us to enjoy them. I'm sure all the readers will appreciate it a lot.

Thank you!

[Jordi Fabre]

We got the kind permision of the Mineralogical Record to publish the John's article here. It would be already published, but today we had problems with one of our computers, so I will do it at Tuesday.

Jordi

[Duncan Miller]

Hello John

Your photograph of the "screw dislocation" in beryl has had me puzzling over a similar crystal that I bought years ago from a deceased estate (so I don't know its provenance, possibly the same as yours?). I shall post a composite photograph of it immersed in oil, from two different points of view. This crystal is 55 mm long and has several of these helical inclusions, some running from end to end. Where they crop out at the ends, the cores don't appear to be hollow, but they could be microscopic tubes. There are plenty of very fine straight ones in this specimen. I have two questions.

First, are these really dislocations? I thought dislocations were microscopic lattice defects requiring transmission electron microscopy to image them. Please correct me if I am wrong.

Second, if they are not dislocations what are they? They certainly do look screw-shaped, but the screw blades do not run all the way around, and under magnification they look more like slightly twisted planar outgrowths or possibly even cracks. Some cores have blades/cracks emanating both right and left. Their spacing is amazingly regular, which means there must be some crystallographic control; but it cannot be cleavage, which in beryl is imperfect and parallel to the basal pinacoid {0001}. These blade-like features are oblique to the basal plane. Could I ask you please to look closely at your specimen to see if you concur?

I don't have an answer to the question of their identity, but if I ever get around to faceting this specimen (two faces were ground already when I got it) I will try to analyse an exposed core to see if there is a second mineral present.

Duncan Miller

[John S. White]

Xenolithos:

There is no doubt in my mind that your crystal came from the same pegmatite as mine. The inclusions appear identical. I agree that the "screw" does not resemble what we tend to think of when referring to a screw dislocation, but I cannot imagine any other mechanism that could produce helical designs in the crystal, particularly ones that are paralell to the "c" axis, as these are. The good news is that John Rakovan at Miami University in Ohio is initiating a study of this phenomenon and I will invite him to respond to your comments. Attached is a close-up photo of my beryl, photo by John Koivula, who calls it a growth spiral.
(for further discussion follow this link https://www.mineral-forum.com/message-board/viewtopic.php?p=13653&highlight=#13653).

Carles Millan, I love your taste in specimens, each is elegant in its own way, and the photos are outstanding. Thanks for sharing them with us. I will post some single crystal photos that were not used in the article.