For education topics/questions http://www.mindat.org/msgboard-62.html Sun, 29 Nov 2009 01:45:25 +0000 Phorum 5.2.8-RC1 http://www.mindat.org/forum.php?read,62,160369,160376#msg-160376 http://www.mindat.org/forum.php?read,62,160369,160376#msg-160376
Having had many pieces of natural Jet, I've never once had it sweat on me.

It could be that they are selling something else as Jet.

And if it was oiled, it could be that under hot conditions, it would sweat.

I would doubt that any true Jet would have much (If any) liquid water in it.

My specialty is Gem Minerals and I have seen other things called Jet, like dyed hardwoods, stones, etc.

Greetings,

-Bri]]> Bri Dragonne Education Mon, 16 Nov 2009 19:39:43 +0000 http://www.mindat.org/forum.php?read,62,160369,160369#msg-160369 http://www.mindat.org/forum.php?read,62,160369,160369#msg-160369
Today, someone asked if Jet could sweat? My logical brain says that since Jet is a type of coal and coal is porous, that humidity and such could cause this. But what about tumbled Jet, or jet that has something like wax smoothed over the surface? This one has me flummoxed. Any thoughts??

Thanks!]]> Kristi Huggins Education Mon, 16 Nov 2009 18:48:01 +0000 http://www.mindat.org/forum.php?read,62,150367,159682#msg-159682 http://www.mindat.org/forum.php?read,62,150367,159682#msg-159682
i.e. sublimation from a gas; sublimation of a solid.

Sadly (or happily) the English language is quite cheerful on being mangled in this way, at least in informal usage.

When discussing mineralising fluids with primarily CO₂ as the solvent, we used to refer to fractional exsublimation as the process of resublimation of specific minerals from the fluid.

Of course, as Frank says, it's just linguistic (until you need to publish a formal paper ... oh dear!)]]> Alysson Rowan Education Tue, 10 Nov 2009 16:07:34 +0000 http://www.mindat.org/forum.php?read,62,158324,158358#msg-158358 http://www.mindat.org/forum.php?read,62,158324,158358#msg-158358 John Stolz Education Mon, 02 Nov 2009 01:05:12 +0000 http://www.mindat.org/forum.php?read,62,158324,158329#msg-158329 http://www.mindat.org/forum.php?read,62,158324,158329#msg-158329
Best to avoid such useless varietal names.]]> Philippe M. Belley Education Sun, 01 Nov 2009 18:33:11 +0000 http://www.mindat.org/forum.php?read,62,158324,158324#msg-158324 http://www.mindat.org/forum.php?read,62,158324,158324#msg-158324
OK, I think I'm okay now.

Anyway, the hessonite page on MinDat gives no details other than a picture. Wiki, offers nothing; RUFF doesn't have an entry.

TIA/John]]> John Stolz Education Sun, 01 Nov 2009 17:28:26 +0000 http://www.mindat.org/forum.php?read,62,127799,152081#msg-152081 http://www.mindat.org/forum.php?read,62,127799,152081#msg-152081
Your daughter is very lucky having parents who have the capability to support her interest.
She will find many interesting things in here.

A month ago I showed the site to a 10 year "young" man!
he was so hooked that he in the evening managed to crash their home PC!]]> Peter Lyckberg Education Wed, 16 Sep 2009 11:42:49 +0000 http://www.mindat.org/forum.php?read,62,150612,150885#msg-150885 http://www.mindat.org/forum.php?read,62,150612,150885#msg-150885 Alfredo Petrov Education Fri, 04 Sep 2009 15:50:49 +0000 http://www.mindat.org/forum.php?read,62,150612,150882#msg-150882 http://www.mindat.org/forum.php?read,62,150612,150882#msg-150882 Maryella Education Fri, 04 Sep 2009 15:36:14 +0000 http://www.mindat.org/forum.php?read,62,150612,150769#msg-150769 http://www.mindat.org/forum.php?read,62,150612,150769#msg-150769 maryella Education Thu, 03 Sep 2009 07:07:16 +0000 http://www.mindat.org/forum.php?read,62,150612,150626#msg-150626 http://www.mindat.org/forum.php?read,62,150612,150626#msg-150626 David Von Bargen Education Wed, 02 Sep 2009 02:01:21 +0000 http://www.mindat.org/forum.php?read,62,150612,150619#msg-150619 http://www.mindat.org/forum.php?read,62,150612,150619#msg-150619 Mark Rheinberger Education Wed, 02 Sep 2009 00:02:27 +0000 http://www.mindat.org/forum.php?read,62,150612,150612#msg-150612 http://www.mindat.org/forum.php?read,62,150612,150612#msg-150612 Maryella Education Tue, 01 Sep 2009 22:42:59 +0000 http://www.mindat.org/forum.php?read,62,150367,150373#msg-150373 http://www.mindat.org/forum.php?read,62,150367,150373#msg-150373
Cheerz!]]> Łukasz Kruszewski Education Sun, 30 Aug 2009 14:10:22 +0000 http://www.mindat.org/forum.php?read,62,150367,150370#msg-150370 http://www.mindat.org/forum.php?read,62,150367,150370#msg-150370 VLS-growth is much more interesting to talk about :-)
Cheers!]]> Frank de Wit Education Sun, 30 Aug 2009 13:56:34 +0000 http://www.mindat.org/forum.php?read,62,150367,150367#msg-150367 http://www.mindat.org/forum.php?read,62,150367,150367#msg-150367
In many papers devoted to gas vents and gas condensation processess, I meet with the term SUBLIMATION as the process ruling the formation of CRYSTALLINE (solid) phases.

And it seems to be wrong, as

Gas CAN'T SUBLIME.... it can RESUBLIME. Sublimation is the process of the conversion of SOLID (in this case: mineral) phase into the GASEOUS phase. Thus salammoniac can sublime, but the parental gaseous fluid cannot, just because its GASEOUS.

Then, is SALAMMONIAC (2) produced by sublimation of SALAMMONIAC (1) from the dust (as was proposed by friend of mine), or anything like that???

What do You think?

Regards,

Luke K.]]> Łukasz Kruszewski Education Sun, 30 Aug 2009 13:44:20 +0000 http://www.mindat.org/forum.php?read,62,140655,143926#msg-143926 http://www.mindat.org/forum.php?read,62,140655,143926#msg-143926
Another great resource on the subject is the Sept/Oct 1995 issue of Rocks and Minerals which I got on back order. I thanks Daniel Russell for pointing it out to me! Great resource on twinning!

Thanks again
Bob]]> Jessica and Robert Simonoff Education Sat, 04 Jul 2009 16:44:28 +0000 http://www.mindat.org/forum.php?read,62,140655,140757#msg-140757 http://www.mindat.org/forum.php?read,62,140655,140757#msg-140757

[www.quartzpage.de]]]> David Von Bargen Education Sun, 07 Jun 2009 13:56:32 +0000 http://www.mindat.org/forum.php?read,62,140655,140756#msg-140756 http://www.mindat.org/forum.php?read,62,140655,140756#msg-140756
Parallel growth aquamarine is not a twin because the would-be-mirror-plane that is added is not new. This is because aquamarine is in the hexagonal system and the would-be-twin-plane is parallal to an existing mirror plane. So far so good.

But in the case of quartz, it is trigonal, so the "would-be-twin-plane" is not parallel to an existing plane. This would be a new symmetry added. So what is it that makes quartz parallel growth not be considered twinning?

Thanks for you help and patience]]> Jessica and Robert Simonoff Education Sun, 07 Jun 2009 13:27:25 +0000 http://www.mindat.org/forum.php?read,62,140655,140741#msg-140741 http://www.mindat.org/forum.php?read,62,140655,140741#msg-140741 David Von Bargen Education Sun, 07 Jun 2009 06:14:50 +0000 http://www.mindat.org/forum.php?read,62,140655,140721#msg-140721 http://www.mindat.org/forum.php?read,62,140655,140721#msg-140721
So does the above mean that a parallel growth quartz (trigonal) would be a twin?

Thanks]]> Jessica and Robert Simonoff Education Sun, 07 Jun 2009 00:30:43 +0000 http://www.mindat.org/forum.php?read,62,140655,140659#msg-140659 http://www.mindat.org/forum.php?read,62,140655,140659#msg-140659 If you already haven't found it.
[www.tulane.edu]]]> David Von Bargen Education Sat, 06 Jun 2009 10:28:42 +0000 http://www.mindat.org/forum.php?read,62,140655,140655#msg-140655 http://www.mindat.org/forum.php?read,62,140655,140655#msg-140655
Thanks]]> Jessica and Robert Simonoff Education Sat, 06 Jun 2009 04:21:01 +0000 http://www.mindat.org/forum.php?read,62,127799,139271#msg-139271 http://www.mindat.org/forum.php?read,62,127799,139271#msg-139271

In case anyone reads this and is trying to learn the subject at an intro level, a great resource I found - easy to understand is: [www.tulane.edu]]]> Jessica and Robert Simonoff Education Tue, 26 May 2009 03:56:29 +0000 http://www.mindat.org/forum.php?read,62,138714,138720#msg-138720 http://www.mindat.org/forum.php?read,62,138714,138720#msg-138720 EMJ]]> Evan Johnson Education Wed, 20 May 2009 18:59:43 +0000 http://www.mindat.org/forum.php?read,62,138714,138714#msg-138714 http://www.mindat.org/forum.php?read,62,138714,138714#msg-138714
Here's a video of this guy. It would be interesting to see what ya'll can come up with.

[www.youtube.com]]]> Janetta Br Education Wed, 20 May 2009 18:16:59 +0000 http://www.mindat.org/forum.php?read,62,136539,136539#msg-136539 http://www.mindat.org/forum.php?read,62,136539,136539#msg-136539 Charlie Mc Education Sun, 03 May 2009 03:31:00 +0000 http://www.mindat.org/forum.php?read,62,127799,127872#msg-127872 http://www.mindat.org/forum.php?read,62,127799,127872#msg-127872 Albert Mura Education Sat, 21 Feb 2009 20:05:11 +0000 http://www.mindat.org/forum.php?read,62,127799,127854#msg-127854 http://www.mindat.org/forum.php?read,62,127799,127854#msg-127854
Don S.]]> Don Saathoff Education Sat, 21 Feb 2009 18:06:34 +0000 http://www.mindat.org/forum.php?read,62,127799,127850#msg-127850 http://www.mindat.org/forum.php?read,62,127799,127850#msg-127850 Crystalography can be a complex subject to fully understand, but sound like she's well suited to appreciate it. In the front few pages of the Simon & Schuster's guide to Rocks and Minerals (pgs. 16-21), there is a "basic" explanation of crystal chemistry, and a very nice series of crystal charts for each system, including line drawings and a short list of minerals which fall into each system. (it's also a nice field guide book for her as well).

What I recommend is that you two take from this text and series of charts and build your own guide book from it. Nothing will help you better understand this system and terminology than to pull the basics together for yourselves! Using a three ring binder, first create "chapter" pages for each basic system (Isometric, Hexagonal/hex, Hexagonal/tri-rhom, Tetragonal, Orthorhombic, Monoclinic and Triclinic). You can write down info in a more simplified form, add images of the mineral species which fall under each system, draw a basic crystal model, what ever! You can later refine the guidebook by adding pages for the various class and degree of symmetry for each "system" if you both have enjoyed the project thus far. Most importantly, all along this process, remember to build yourself a glossary of terms. When you come to a term which requires some explanation (i.e. unit cell, mirror plane, various elements of symmetry, axis, equivalent, etc.,), look it up and write it down as simply and straight forward as possible, so you can refer back to it later (sadly, rarely will you find a usable glossary of terms in a book advanced enough to answer the questions you posed above).

A good "hands on" project, gathering the info yourselves and pulling it together into more "digestible" tidbits will really help it sink in, remember to keep this fun too! You two can peruse the mineral gallery here and choose together, the "coolest" pics of minerals to print out and add to the project pages. As with anything, once you have the basics, systems, classes and terminology down pat, you can then breeze through a more thorough text on the subject, which it sounds like she's already itching for!


MRH (Montesorri School Dad)]]> Mark Heintzelman Education Sat, 21 Feb 2009 17:26:40 +0000