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

From: David Gunning <davidgunning_at_meteoritecentral.com>
Date: Thu, 30 Sep 2010 23:23:16 -0400 (EDT)
Message-ID: <3817.69.50.53.154.1285903396.squirrel_at_webmail.fairpoint.net>

Aloha,

Thanks for the note. Yeah, that Brother Guy fellow is a rare bird. I am
not so concerned with taking precise specific gravity value measurements
(I've been doing that for years) so much as wanting to get the word out
that there are ways of dealing with potential contamination issues, which
seems to be the big bugaboo for most folks. The actual process of taking
and achieving an exacting specific gravity measurement is so straight
forward a child could do it.

Appears to me that the willingness to measure specific gravity may be a
reasonably accurate bellwether of whether a person is really, really
interested in meteorites for what they are, and might be, as opposed to
being used as mere lucrative commodities to be bought and sold.

Such is life!

Dave Gunning



> Aloha -
>
> Just started looking through this:
>
> http://homepage.mac.com/brother_guy/.Public/Meteorite%20Densities.pdf
>
> and at the end, it has grain density And bulk density for a whole bunch
> of meteorites, and meteorite classes... (yeah, it's got the porosity
> data too...)
>
> In that listing, it doesn't give the sub-class of H / L / LL, but that
> should be able to be looked up if you want to get finer information out
> of this data.
>
> Now, this doesn't address how to do it at home, other than replicating
> the process that they used (small glass beads - and all)
>
> Looked pretty interesting....
>
> cheers = ted
>
> --- On Thu, 9/30/10, David Gunning <davidgunning at fairpoint.net> wrote:
>
>> From: David Gunning <davidgunning at fairpoint.net>
>> Subject: Re: [meteorite-list] [Fwd: RE: Specific Gravity Question]
>> To: "Sterling K. Webb" <sterling_k_webb at sbcglobal.net>
>> Cc: meteorite-list at meteoritecentral.com
>> Date: Thursday, September 30, 2010, 2:44 PM
>>
>> 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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>> >
>> >
>>
>>
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Received on Thu 30 Sep 2010 11:23:16 PM PDT