[meteorite-list] [Meteorites] http://phys.org/news184402061.html

From: Sterling K. Webb <sterling_k_webb_at_meteoritecentral.com>
Date: Sun, 1 Jul 2012 18:21:33 -0500
Message-ID: <0B6506AA87CA44438D1D1C60BB667F89_at_ATARIENGINE2>

E Man, Pete, List,

> Lonsdalite is the mineral form found in carbonados...

Not a mineralogist, even an amateur one, but the
statement that seems to say that carbonados are
made of lonsdaleite:made my nose tickle, so I went
to the "consensus" source.

    "Carbonado, commonly known as the "Black
Diamond", is a natural polycrystalline diamond
found in alluvial deposits in the Central African
Republic and Brazil.. .No distinctive high-pressure
minerals, including the hexagonal carbon polymorph,
lonsdaleite, have been found as inclusions in
carbonados, although such inclusions might be
expected if carbonados formed by meteorite impact."

    "Lonsdaleite occurs as microscopic crystals associated
with diamond in several meteorites: Canyon Diablo,
Kenna, and Allan Hills 77283. It has also been reported
from the Tunguska impact site. It also naturally occurring
in non-bolide diamond placer deposits in the Sakha
Republic. It has also been found in sediments dated to
12,900 years ago, at Lake Cutizeo, in the state of Guanajuato,

What am I missing?

Sterling K. Webb
----- Original Message -----
From: "MstrEman" <mstreman at gmail.com>
To: <pshugar at messengersfromthecosmos.com>
Cc: "The List" <meteorite-list at meteoritecentral.com>
Sent: Sunday, July 01, 2012 9:33 AM
Subject: Re: [meteorite-list] [Meteorites]

> Not taking from what Pete said, lonsdalite isn't a newly identified
> mineral, per se. It has been around a few years but the explanation as
> to how both types of crystals formed "during entry" is bogus. Boron
> nitrate may or may not be formed on exposure to atmospheric
> nitrogen-- but it would only be on the surface and not in the
> interior.
> I haven't read the background on boron nitrate's formation
> conditions but I can't imagine a scenario that could impart any
> nitrogen into the COLD interior during entry. Either way the text for
> this report doesn't pass the smell test.
> As to lonsdaleite, "entry pressures" short of cosmic velocity impact
> with the ground are not high enough to create this polymorph of
> carbon. It is far more probable that lonsdalite is literally burned up
> in the presence of atmospheric oxygen as fast as it is uncovered.
> Lonsdalite is the mineral form found in carbonados. Its pentamount
> hardness is why drill bit manufacturers had to embed them uncut
> directly in the the bit casting. Until the recently found technique
> cutting/burning with a laser, there was nothing that could cut them.
> Another case of a out of work sports writer moonlighting as a science
> writer perhaps? If this is the researcher's real belief then he is
> advocating a whole new arm of physics/chemistry.
> Elton
> On 6/30/12, pshugar at messengersfromthecosmos.com
> <pshugar at messengersfromthecosmos.com> wrote:
>> Hello list,
>> The implications of these findings are, to say the least, staggering.
>> has this been confirmed in other Ureilite meteorites? Such as Novo
>> Urie,
>> or others?
>> For years, diamonds were the standard of hardness, and now that's
>> all out the window!!!!
>> Pete
> ______________________________________________
> Visit the Archives at
> http://www.meteoritecentral.com/mailing-list-archives.html
> Meteorite-list mailing list
> Meteorite-list at meteoritecentral.com
> http://six.pairlist.net/mailman/listinfo/meteorite-list
Received on Sun 01 Jul 2012 07:21:33 PM PDT

Help support this free mailing list:

Yahoo MyWeb