[meteorite-list] Micromounts and weights - Standards Vary

From: Greg Catterton <star_wars_collector_at_meteoritecentral.com>
Date: Fri, 1 Jul 2011 17:50:52 -0700 (PDT)
Message-ID: <1309567852.16338.YahooMailClassic_at_web46416.mail.sp1.yahoo.com>

There is a scale called digiweigh that works awesome. accurate to a grain scale I use to reload ammo with. They last only about 2 years with heavy use but are great in my opinion.

Greg Catterton
www.wanderingstarmeteorites.com
IMCA member 4682
On Ebay: http://stores.shop.ebay.com/wanderingstarmeteorites
On Facebook: http://www.facebook.com/WanderingStarMeteorites


--- On Fri, 7/1/11, Richard Montgomery <rickmont at earthlink.net> wrote:

> From: Richard Montgomery <rickmont at earthlink.net>
> Subject: Re: [meteorite-list] Micromounts and weights - Standards Vary
> To: "Michael Blood" <mlblood at cox.net>, "Met. Mike Bandli" <fuzzfoot at comcast.net>, "Met. Michael Gilmer" <meteoritemike at gmail.com>, "Meteorite List" <meteorite-list at meteoritecentral.com>
> Date: Friday, July 1, 2011, 7:53 PM
> Hi List,
>
> As a non-dealer, but the ocassional passer-on-of-specimens,
> (normally the ocassional? SA batches or other
> noteables), I use an x.xx scale yet have always quoted the
> weight to x.x -(.x) ...with respect to my error potential.
> Quoting at least a -.x (i.e. 68.8gr instead of the scale's
> reading of 68.9 or 68.92) to at least insure satisfaction, I
> don't expect anyone to get PO-ed when it weighs more than
> quoted.? Yet this does invite an inaccuracy element
> with regard to my labels.
>
> I'd love to hear some feedback here, so please chime in.
>
> For the specimens with a stellar provenence
> chain-of-custody, I still check and adjust.? Crumbs can
> fall...
>
> Or, the original seller may have weighed the specimen from
> 30K feet :>)
>
> -Richard Montgomery
>
>
> ----- Original Message ----- From: "Michael Blood" <mlblood at cox.net>
> To: "Met. Mike Bandli" <fuzzfoot at comcast.net>;
> "Met. Michael Gilmer" <meteoritemike at gmail.com>;
> "Meteorite List" <meteorite-list at meteoritecentral.com>
> Sent: Friday, July 01, 2011 1:37 PM
> Subject: spam: Re: [meteorite-list] Micromounts and weights
> - Standards Vary
>
>
> > Hi Mike and all,
> >? ? ? ? I absolutely agree. I used
> to use a $500 digital and now
> > Use a $135 digital and I consider them both about as
> accurate
> > As the other ~ deduct one decimal point for absolute
> accuracy.
> > (it is likely far closer than that, but one should not
> proclaim
> > a specific weight, IE .007g (7mg) unless one has a
> serious
> > balance beam in an air tight setup. A royal pain in
> the a**
> > And extremely costly.
> >? ? ? ? However, for the most part,
> I always sell micromounts - the
> > Ones less than 10mg, based on VISUAL COMPARISON. That
> is
> > What I look for for my own collection... If I want
> something that
> > Is so small, then the size is far more important to me
> than the mass.
> >? ? ? ? BTW, a micromount has
> traditionally been defined as any
> > Specimen that fits into an old style 1" X 1" square
> display box.
> > The new, vastly superior membrane boxes are
> considerably larger
> > And can hold a decent sized macromount equally well as
> a micromount.
> >? ? ? ? Best regards, Michael
> >
> > On 6/30/11 4:52 PM, "Met. Mike Bandli" <fuzzfoot at comcast.net>
> wrote:
> >
> >> A little perspective on milligrams:
> >>
> >> There are a lot of meteorite mg weights out there
> that not accurate. We can
> >> thank these new, cheap Chinese digital scales that
> promise accuracies of +/-
> >> 1mg or less, which are a complete joke. I bought
> one in Tucson to test it
> >> out against my high-end calibrated machine and it
> was off by about 10 mg on
> >> average for pieces 50 to 100 mg and 5 mg on
> average for pieces 10 to 50 mg.
> >> Anything fewer than 10 mg - forget about it. The
> calibration weights it came
> >> with were even more laughable...
> >>
> >> In reality, in order to be able to accurately
> measure mg, you need a machine
> >> that has been recently leveled and calibrated
> in-situ. I have a recently
> >> leveled/calibrated mechanical scale whose tare
> changes by the hour due to
> >> changes in the weather. It even picks up the
> subtle vibration of the
> >> dishwasher downstairs.
> >>
> >> Bottom line - a $100 mg scale isn't going to get
> you the accuracy needed to
> >> accurately measure true mg. Since most people
> can't afford the hundreds to
> >> thousands it costs for an accurate mg scale, I
> don't expect most mg weights
> >> advertised to be truly accurate. They're close...
> >>
> >> Just my 2 mg worth (+/- 1mg)...
> >>
> >> ----------------------------------------------
> >> Mike Bandli
> >> Historic Meteorites
> >> www.HistoricMeteorites.com
> >> and join us on Facebook:
> >> www.facebook.com/Meteorites1
> >> IMCA #5765
> >> -----------------------------------------------
> >>
> >>
> >>
> >> -----Original Message-----
> >> From: meteorite-list-bounces at meteoritecentral.com
> >> [mailto:meteorite-list-bounces at meteoritecentral.com]
> On Behalf Of Michael
> >> Gilmer
> >> Sent: Thursday, June 30, 2011 4:17 PM
> >> To: Meteorite List
> >> Subject: [meteorite-list] Micromounts and weights
> - Standards Vary
> >>
> >> Hi Listees and Micronauts,
> >>
> >> There has been some discussion recently about
> people buying
> >> micromounts from a vendor on eBay and not getting
> the weights they
> >> were promised.? I thought I would throw out
> some thoughts on micros,
> >> since those are my bread and butter.
> >>
> >> First, the definition of "micromount" is
> relative.? There is no
> >> set-in-stone size bracket for what defines a
> micromount.? It seems to
> >> me that the general consensus is that micromounts
> are in the 1g range
> >> for the more common types and sub-gram in weight
> for the rare types.
> >> Very rare falls or planetaries are commonly sold
> by the milligram.
> >> Rockhounds tend to equate meteorite micromounts
> with mineral
> >> thumbnails.? But generally speaking, most
> micromounts on the market
> >> today are in the sub-gram (<1g) range.
> >>
> >> Ideally, a micromount should be visually appealing
> (such a well
> >> polished, thin part slice with good surface area
> to weight ratio) and
> >> big enough to identify the lithology of the
> type/fall, while at the
> >> same time being cheap enough to afford on a
> limited budget.
> >>
> >> The more preparation that goes into making a given
> micromount, the
> >> higher the price, generally speaking.? At
> some point, it's not
> >> financially viable to put a lot of cutting and
> polishing work into
> >> piece of common find that is only worth a buck or
> two a gram.
> >> Smaller micros are difficult to work with during
> preparation, for
> >> obvious reasons, so many of the micromounts seen
> on the market are
> >> unpolished, rough, or broken.
> >>
> >> What motivates a person to collect micromounts
> varies from person to
> >> person, but the most commonly cited reason for
> buying micros is to
> >> temporarily fill a void in a type
> collection.? It could be a
> >> petrologic type, a find from a given geographic
> area, a fall from a
> >> specific date, etc.? Often a micromount is a
> temporary measure until a
> >> nicer specimen can be acquired, or until the
> needed finances to buy a
> >> larger piece can be saved up.? For the very
> rare types and
> >> planetaries, a micromount might be the best hope
> for a collector on a
> >> restricted budget.
> >>
> >> There are a couple of schools of thought when it
> comes to dealing and
> >> selling micromounts - some dealers sell specimens
> by weight (by
> >> milligram, even for specks) or some dealers offer
> specimens by the
> >> piece (by eye/photo).? For the most part, I
> am of the latter school
> >> that sells micros by the piece.? That means I
> don't weigh each and
> >> every micromount, unless it is a very rare and
> valuable meteorite such
> >> as a planetary or historical fall.? Each
> dealer has their own methods
> >> for handling micromounts and we those aren't
> really relevant to the
> >> discussion at hand.
> >>
> >> When weighing micromounts, one must use an
> accurate scale that is
> >> sensitive to 1 milligram - the good ones are used
> by diamond and gem
> >> dealers.? There are many brands of these
> scales which range in quality
> >> and accuracy.? When dealing with small specks
> that weigh a milligram
> >> or two, the readings can vary from unit to unit
> when weighing the same
> >> specimen.? If a buyer pays for and is
> promised a micro that weighs
> >> 100mg, it better weigh 100mg and not 50mg or
> 80mg.? Sometimes a buyer
> >> gets an added bonus because their personal scale
> is more accurate than
> >> the seller's scale and a promised 100mg micro
> might weigh 120mg or
> >> 150mg. If the seller is not sticking to a strict
> pricing scheme ($/g
> >> or $/mg), then ultimately what matters is if the
> buyer is happy with
> >> their micromount.
> >>
> >>> From a collector's standpoint, it pays to shop
> around for micromounts.
> >>? Unless it's a very rare meteorite, it's easy
> to find several dealers
> >> offering similar-sized specimens for
> widely-varying prices.? One must
> >> also pay close attention to the reputation of the
> seller and the
> >> provenance of rare specimens.? Because micros
> tend to be small (some
> >> are downright tiny), it would be easy for an
> unscrupulous seller to
> >> misrepresent specimens as something more valuable
> than what they truly
> >> are.???Chances are, if you are
> reading this mailing list, you are one
> >> of those people who can find a reputable source
> and who does their
> >> homework before sending payments across oceans on
> fiber-optic cables.
> >>
> >> My own personal meteorite collection (the pieces I
> keep in my cabinet
> >> and are not traded on my website) are mostly
> micromounts and I keep
> >> the majority of them stored in 1.25" gemjars with
> paper labels inside
> >> the bottom, under the foam.? Some people
> prefer membrane boxes, small
> >> Riker boxes, or other storage and display methods,
> but that is the
> >> subject of an entire debate of it's own.? The
> most commonly-seen
> >> container on the micromount market is the gemjar,
> and thus it is a
> >> general rule of thumb that if a specimen will fit
> into a gemjar, then
> >> that specimen could/should be called a
> "micromount".
> >>
> >> Best micro-regards,
> >>
> >> MikeG
> >
> >
> > --
> > Obama is not a brown-skinned anti-war socialist.
> > You are thinking of Jesus.
> > --
> > Add two grains of sugar to everything you say
> > And one of salt to everything you hear.
> >
> >
> >
> >
> >
> >
> >
> > ______________________________________________
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> >
>
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Received on Fri 01 Jul 2011 08:50:52 PM PDT