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Jesse Fisher
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Posted: Mar 24, 2014 22:29 Post subject: Re: New Standards of Excellence in the Mineral Kingdom - M.R. March-April 2014 |
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I have looked through the original book and am unable to find a vanadinite (from anywhere) in it.
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alfredo
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Posted: Mar 24, 2014 22:46 Post subject: Re: New Standards of Excellence in the Mineral Kingdom - M.R. March-April 2014 |
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Of course ALL vivianites are unstable in the presence of light or heat, whether or not from Bolivia, and whether or not associated with pyrite. I recommend keeping them in a cool dark place, wherever they are from. Sometimes one can get Bolivian ones sitting on siderite or wavellite rather than pyrite, so that helps with the acidity problem.
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Jordi Fabre
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Posted: Mar 25, 2014 04:03 Post subject: Re: New Standards of Excellence in the Mineral Kingdom - M.R. March-April 2014 |
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bob kerr wrote: | ...should a specimen that's unstable be included here? I would vote no but others who've bought these that I know from AZ have not seen the decomposition.... |
Although it is true that in very dry climates like in AZ the vivianites seems to maintain, I would not add them to the list considering their tendency to decay and decompose. Even if you live in AZ (or similar) if some day you move to a higher humidity place, then the vivianite will probably "die" so, for a so serious list, I believe it is better not to encourage people to consider the vivianites as one of the "you must have in your collection" by its instability, but... the realgar is already in the article's list, so...
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Peter Megaw
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Posted: Mar 25, 2014 08:28 Post subject: Re: New Standards of Excellence in the Mineral Kingdom - M.R. March-April 2014 |
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So, does accessibility to a collector matter?
I would argue that the Gypsum (var. selenite...sensu strictu) from the Cave of the Giants at Naica as another example of completely resetting the bar...and although they are probably both at least somewhat unstable if removed from the cave, we will never know since they are virtually impossible to remove given their sheer size. I believe Bancroft mentioned the Cave of the Swords in the original...but these render the CoS crystals insignificant.
I also think the cassiterites and scheelites from Pingwu, China are worthy candidates for NSE.
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bob kerr
Joined: 13 Nov 2011
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Location: Monroeville PA
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Posted: Mar 25, 2014 10:08 Post subject: Re: New Standards of Excellence in the Mineral Kingdom - M.R. March-April 2014 |
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Jesse Fisher wrote: | I have looked through the original book and am unable to find a vanadinite (from anywhere) in it. |
I would think John and Tom automatically assumed that the Moroccan vanadinites were already included in the Bancroft book. But these vanadinites certainly belong on the top of this list as the second best vanadinite locality (probably the North Geronimo Mine in AZ) just doesn't compete.
bob
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bob kerr
Joined: 13 Nov 2011
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Posted: Mar 25, 2014 10:16 Post subject: Re: New Standards of Excellence in the Mineral Kingdom - M.R. March-April 2014 |
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I note in the MR article that "new species from a single find" like olmiite are not included. i guess I would argue that they should be included as this find "sets the bar" from which all past and future finds should be compared - even if there was no previous finds.
And while i'm on Africa - I would also lobby for the sturmanites and ettringites from N'Chwaning as candidates for inclusion on the list.
bob
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Jordi Fabre
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Posted: Mar 25, 2014 10:19 Post subject: Re: New Standards of Excellence in the Mineral Kingdom - M.R. March-April 2014 |
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bob kerr wrote: | ....but these vandinites certainly belong on the top of this list as the second best vanadinite locality (probably the North Geronimo Mine in AZ) just doesn't compete. |
Familiar with the Moroccan vanadinites as well as the North Geronimo/Pure Potential vanadinites through the specimens bought by Sr. Folch in US in the 50s-60s. I should say that the difference is gigantic.
One reason for a kind of lower visibility of the Moroccan ones could be that they are so fragile that not too many arrive in the US, but if you take a look in many European collections...
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Les Presmyk
Joined: 06 Dec 2007
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Location: Gilbert, AZ
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Posted: Mar 25, 2014 10:57 Post subject: Re: New Standards of Excellence in the Mineral Kingdom - M.R. March-April 2014 |
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The Moroccan vanadinites are the finest in the world. While Arizona localities may have held that title for decades, this has not been the case for the past 40 years. North Geronimo/Pure Potential is probably Arizona's best vanadinite locality, followed by the Old Yuma Mine and then the Apache Mine.
As we were doing research for our book, it was interesting to read the old ads for minerals. In 1890, when vanadinites were coming out of Arizona, and what were then world-class specimens, dealers were charging up to $30 for a cabinet sized piece. Visions of large and multiple crystals attractively arranged on matrix dance in one's head. And, pieces that surely would bring thousands of dollars today because after all, $30 was a month's salary back then. This is certainly the case with the Bisbee and Morenci azurites and malachites from this era. However, you will be disappointed to see one of these vanadinites today. They are still $30 specimens and only if someone wants the old label or a bit of history.
Sturmanite and Ettrigite are certainly contenders for the list. What about Chinese scheelites? The Chinese scheelites are certainly heads and shoulders above Korea (color and size), the Morro Vehlo gold mine in Brazil (size) and even Arizona, although this locality is the closest one in terms of size and color.
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Les Presmyk
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Posted: Mar 25, 2014 11:05 Post subject: Re: New Standards of Excellence in the Mineral Kingdom - M.R. March-April 2014 |
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To Peter Megaw's recommendations, if vivianite and other minerals that are not stable in certain environments are disqualified, then there should also be criteria that limits the size to something that can be collected and placed in a display case. After all, the gypsum cave he refers to will someday be back under water and unavailable for viewing.
I also considered the cassiterites from China but they are not a significant step up, at least using the MR article criteria, from the great cassiterites from Araca, Bolivia.
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Susan Robinson
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Posted: Mar 25, 2014 12:59 Post subject: Re: New Standards of Excellence in the Mineral Kingdom - M.R. March-April 2014 |
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I would think the antimony crystals found at the Lake George Antimony mine, Lake George, New Brunswick, Canada, would certainly qualify?
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Jordi Fabre
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Posted: Mar 25, 2014 13:02 Post subject: Re: New Standards of Excellence in the Mineral Kingdom - M.R. March-April 2014 |
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Susan Robinson wrote: | I would think the antimony crystals found at the Lake George Antimony mine, Lake George, New Brunswick, Canada, would certainly qualify? |
Absolutely Susan. Far better than any other...
I add a good example from the A. E. Seaman Mineral Museum, Michigan Technical University, Houghton, Michigan thread.
Description: |
This photo of one of these superb Antimony element from Lake George Mine is part of the wonderful series of images of the Seaman Mineral Museum published by John Jaszczak in the thread: "A. E. Seaman Mineral Museum, Michigan Technical University, Houghton, Michigan" |
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bob kerr
Joined: 13 Nov 2011
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Posted: Mar 25, 2014 15:04 Post subject: Re: New Standards of Excellence in the Mineral Kingdom - M.R. March-April 2014 |
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how about including the brochantites from Milpillas - I don't know of a close second best occurrence. the Lindstrom trophy winner this year was one (see photo attached) - and there are more that are better.
bob.
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Jordi Fabre
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Posted: Mar 25, 2014 15:06 Post subject: Re: New Standards of Excellence in the Mineral Kingdom - M.R. March-April 2014 |
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bob kerr wrote: | how about including the brochantites from Milpillas... |
I have no doubts about them. I don't know better...
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Peter Megaw
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Posted: Mar 25, 2014 16:09 Post subject: Re: New Standards of Excellence in the Mineral Kingdom - M.R. March-April 2014 |
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Milpillas Rules! (I was waiting to get my latest shots from Jeff Scovil to post a decent brochantite from there)
The volborthites are very significant too...although perhaps too rare to make the "availability" cut.
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John S. White
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Posted: Mar 26, 2014 04:27 Post subject: Re: New Standards of Excellence in the Mineral Kingdom - M.R. March-April 2014 |
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Don't know when the antimony was available but the brochantite appeared too late to be included in the article, which was written about a year before it was published.
_________________ John S. White
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Jordi Fabre
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Posted: Mar 28, 2014 14:45 Post subject: New Standards of Excellence in the Mineral Kingdom - Perovskites from Russia |
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Is clear that the major sources of "new Standards of Excellence" in the last times have been Russia and China, two giants which came to the collector's specimens just recently.
One good example of this, not listed in the article, could be the Perovskites from Zlatoust, Chelyabinsk Oblast, Russia.
Nothing to compare was mined before, at least as far as i know.
Description: |
Perovskite on Calcite Zlatoust, Chelyabinsk Oblast, Russia Specimen size: 2.9 × 2.4 × 2.2 cm Main crystal size: 1.5 × 1.2 cm Photo: Reference Specimens |
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John S. White
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Posted: Mar 29, 2014 08:52 Post subject: Re: New Standards of Excellence in the Mineral Kingdom - M.R. March-April 2014 |
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I thought the Russian perovskites appeared much too early to be included, but they certainly should be considered in any new listing.
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Jordi Fabre
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Posted: May 01, 2014 16:11 Post subject: New Standards of Excellence in the Mineral Kingdom - Zoisite (var tanzanite) |
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I believe no one will argue this! ;-)
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A great example from Michael Shaw: Zoisite var. tanzanite D Block, Merelani Mines, Lelatema Mts., Manyara Region, Tanzania 1.5 x 1.9 cm Deep blue tanazanite crystals in parallel growth. Photo: "Crosstimber" |
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Recently unusual bluish Prehnite appeared together with the tanzanites:
Zoisite var tanzanite and Prehnite Merelani Hills, Lelatema Mountains, Arusha, Tanzania Specimen size: 3.6 × 1 × 1.2 cm Main crystal size: 3.6 × 1.2 cm Mined in 2010 Photo: Reference Specimens |
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Jordi Fabre
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Posted: Apr 20, 2015 08:03 Post subject: Re: New Standards of Excellence in the Mineral Kingdom - M.R. March-April 2014 |
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One more addition to the New Standards of Excellence "wonder list" : the Plumbogummites coating or replacing Pyromorphite from the Yangshuo Mine, Yangshuo County, Guilin, Guangxi Zhuang, China.
Mineral: | Plumbogummite coating Pyromorphite |
Locality: | Yangshuo / Laohu area, Haiyang Mountains, Guilin Prefecture, Guangxi Zhuang Autonomous Region, China | |
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Dimensions: | Specimen size: 2 × 1.9 × 1.2 cm |
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Mineral: | Plumbogummite after Pyromorphite |
Locality: | Yangshuo / Laohu area, Haiyang Mountains, Guilin Prefecture, Guangxi Zhuang Autonomous Region, China | |
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Dimensions: | Specimen size: 2.4 × 1.6 × 2 cm |
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bob kerr
Joined: 13 Nov 2011
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Posted: Apr 20, 2015 10:01 Post subject: Re: New Standards of Excellence in the Mineral Kingdom - Zoisite (var tanzanite) |
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Jordi Fabre wrote: | I believe no one will argue this! ;-) |
with respect to the tanzanites - maybe - only because how can you tell if the color is natural or heat treated? I really don't think you can and EVERYONE seems to claim the color is natural until you talk with some locals who say EVER tanzanite is heat treated. highly suspicious.
bob
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