[meteorite-list] [Fwd: RE: Specific Gravity Question]

From: David Gunning <davidgunning_at_meteoritecentral.com>
Date: Thu, 30 Sep 2010 20:44:10 -0400 (EDT)
Message-ID: <3400.69.50.53.154.1285893850.squirrel_at_webmail.fairpoint.net>

Hi Sterling,

I've never declined to read any reference that's been offered for my
additional understanding, on any subject matter. More to the point, you
might ought to climb down from your high horse, for a minute, and
actually read the actual intent of my question.

My question centered around the idea of an individual taking their own
specific gravity measurement of their own meteorites.

I take it from your response that you would defer to Brother Consolmagno
for any specific gravity measurements you might be curious about. Just
because the good Brother is associated with the Vatican, I wonder, do you
treat his findings as gospel? If so, good for you.

Now, I am sure the good Brother is very exacting in his methods and
measurements. I have no difficulty with that. Good for him!

Most of his references, however, according to the links you provided,
have to do with measuring the the grain bulk density of asteroids.
That's quite a headful and a rarefied arena I would not presume to know
much about. And has, for the most part, little, if any, practical
application with actually measuring the specific gravity of meteorites.

As may be, I think it's rather silly of you to compare measuring home
grown specific gravity values of meteorites with measuring the bulk grain
density of asteroids (or the bulk grain density of meteorites, for that
matter).

They are horses of different colors.

One valuable insight I was able to glean from the good Brother's writing
is when he suggests that his margin of error in his measurements is
something on the order of plus or minus .07 percent, if I understand
correctly. That agrees with my own estimation of a possible range of
error for ordinary specific gravity measurements for meteorites.

My stated interest has to do with common meteorites (if such a term may
apply!) and how ordinary people might gain more insight into their own
ordinary meteorites (to the extent that any meteorite can be thought of
as being "ordinary"!) by utilizing traditionally proven time worn methods
of measuring the specific gravity of their own space rocks.

Is there something intrinsically wrong with wanting to do that?

Glad tidings!

Dave Gunning







> Hi, Dave,
>
> You should try actually reading the references that
> people give to help you with your question. If you
> had, you would have found the citation to the published
> data in about 30 seconds, just like I did:
>
> Consolmagno, G. J. and D. T. Britt, 1998, The Density
> and Porosity of Meteorites from the Vatican Collection,
> Meteoritics and Planetary Science, vol. 33, p. 1231-1241.
>
> Getting unpaid internet access to a scholarly journal is
> another matter, though.
>
>
> Sterling K. Webb
> ----------------------------------------------------------------------
> ----- Original Message -----
> From: "David Gunning" <davidgunning at fairpoint.net>
> To: <meteorite-list at meteoritecentral.com>
> Cc: <davidgunning at fairpoint.net>
> Sent: Thursday, September 30, 2010 7:08 AM
> Subject: [meteorite-list] [Fwd: RE: Specific Gravity Question]
>
>
>> --------------------------- Original
>> Message ----------------------------
>> Subject: RE: [meteorite-list] Specific Gravity Question
>> From: "David Gunning" <davidgunning at fairpoint.net>
>> Date: Thu, September 30, 2010 7:55 am
>> To: "Peter Scherff" <peterscherff at rcn.com>
>> -------------------------------------------------------------------------
>>
>> Howdy,
>>
>> Thanks for the e-burp.
>>
>> There was no link, however, to the "published data for hundreds of
>> meteorites", mentioned in your e-burp. Why allude to information that
>> cannot be referenced and verified?
>>
>> While it's interesting to read of your specific gravity bead method,
>> there are other less convoluted ways or dealing with the fear of
>> potential contamination in meteorites and mineral samples, in general.
>>
>> What particularly interests me is exploring ways and utilizing lower
>> tech
>> methods that bring the ordinary collector into the the loop.
>>
>> Your suggested method would seem to exclude that possibility.
>>
>>
>>
>>> Hi,
>>>
>>> Here is the way around contamination
>>> http://www.psrd.hawaii.edu/Aug99/densityMeasure.html. Guy Consolmagno
>>> has
>>> published data for hundreds of meteorites.
>>>
>>> Peter
>>>
>>> -----Original Message-----
>>> From: meteorite-list-bounces at meteoritecentral.com
>>> [mailto:meteorite-list-bounces at meteoritecentral.com] On Behalf Of
>>> David
>>> Gunning
>>> Sent: Thursday, September 30, 2010 6:46 AM
>>> To: meteorite-list at meteoritecentral.com
>>> Cc: davidgunning at fairpoint.net
>>> Subject: [meteorite-list] Specific Gravity Question
>>>
>>>
>>> Hi All,
>>>
>>> I'm a confessed specific gravity advocate for all things
>>> mineralogical,
>>> including meteorites. It seems to me that there is very little
>>> useful
>>> specific gravity information on the web concerning meteorites, with
>>> the
>>> singular exception of Randy L. Korotev', excellent website at
>>> Washington
>>> University in St. Louis; an informative website listing various
>>> specific
>>> gravity values for various meteorite types and classifications.
>>>
>>> It occurs to me that many people may not be taking specific gravity
>>> measurements of their meteorite specimens because of some sort of
>>> biased
>>> but unfounded fear of specimen contamination. Is this true?
>>>
>>> One of the benefits of measuring specific gravity is in being able to
>>> spot density anomalies in meteorites. For example, you procure a
>>> small
>>> meteorite specimen of a meteorite has been classified as an "L"
>>> ordinary
>>> stoney chondrite, with a range of specific gravity values, as found
>>> on
>>> Professor Korotev' s.g. list, of between 2.50 and 3.96 (with an
>>> average
>>> s.g. of 3.35). When you, yourself, measure the specific gravity of
>>> your
>>> L chondrite, and it's s.g. value comes in at 4.06, what does that
>>> mean?
>>>
>>> Would such a s.g. reading #1: be possible? And #2: be meaningful?
>>>
>>> Are meteorite specific gravity values exclusively constrained to the
>>> range of values that the scientists peg them at?
>>>
>>> And, if not, if actual specific gravity measurements cam occur
>>> outside
>>> the conventionally accepted range of values of the "experts", should
>>> anyone give a hoot one way or another?
>>>
>>> Best wishes,
>>>
>>> Dave Gunning
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
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>>>
>>
>>
>>
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>
Received on Thu 30 Sep 2010 08:44:10 PM PDT