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Re: Grading, was Re: Meteorites-do you sell your loved ones?
I would just like to add a bit to Kevin and Jim's posting. I agree with the need for
more description, and better images (I am trying all the time!), but not every piece
of Jilin or Allende looks the same. I've had pieces that you cut one way, and cut it
another and it looks totally different. Rocks are NOT like baseball cards, and comic
books. There is no standard we can compare them to. I have been a professional
geologist for about 6 years now, and I have see ALOT of rocks. I could show you two
rocks, both andesites, and you would swear you were seeing a piece of basalt and
granite (to contrast). Meteorites are totally objective. If you don't like the way
a specimen looks when you get it, send it back! If the dealer gives you a hard time,
don't buy from him/her again. Furthermore, a dealer should know basic meteoritics,
astronomy, and geology. There is no excuse for calling a stone an L4 when it is an
H6, I've seen it, and it bothers me. Take a class, read all the books you can, and
be responsible, especially for NEW specimens. Get them officially classified, or
have several other dealers, collectors, instructors, take a look at it.
Jim Hurley wrote:
> Kevin brings up some interesting points about grading.
> I wish every dealer had high-grade digital photos of
> all specimens that were above average in quality.
> I don't mind spending more for high quality, but I feel
> a bit annoyed to get a specimen that doesn't display
> properties that are representative of the type - for
> example, as Kevin says, a Allende specimen should
> exhibit CAI's, and an impact melt should show signs
> of impact and melting, by all means sell me a brecciated
> specimen, but hey, where's the brecciation? Just what does
> oriented with flow lines mean? Shouldn't it be round?
> Sometimes I feel that dealers are the only ones that get the best stuff,
> that I should become a dealer, buy a few kilos, keep the
> one best specimen for myself, and sell the rest. My collection
> would be free because the markup would pay for what I keep.
> This kind of behavior should only be justified if I offered
> some service of value in exchange - such as that pictorial
> catalog I mentioned.
> Many dealers do have images but some are pretty hard to see
> because they've been compressed too much or taken under
> poor conditions, etc.
> I understand how difficult this is to do, updating catalogs
> on the web is time-consuming. But, would you buy a diamond ring
> based on a text description?
> Here is a grade guide that I propose as a start - I only spent
> a minute on it and it's incomplete - it's dufficult to be
> complete and cover all the issues - this grading scale focusses
> only upon appearances, deterioration will tend to lower grades over time.
> For individuals For slices
> ------------------------------ -----------------------------------
> Grade A+ - 100% fusion crust, oriented
> Grade A - 100% fusion crust edge is fully crusted
> no chips displays all properties of its type
> Grade B - 90% fusion crust displays most properties of its type
> some rusting of metal
> Grade C ...
> Grade D fragment, no crust
> Grade E waethered, rusted fragment
> MARSROX@aol.com wrote:
> > We've all purchased
> > specimens that weren't Grade "A" although we paid a good price.
> > Poor slicing, the wrong lubricant that
> > led to the specimen "bleeding", and not much elbow grease going into the
> > polishing.
> > Don't tell me that a specimen of
> > tired Allende w/o a CAI in sight is worth the same as a piece with a
> > brilliant, white CAI and primary and secondary crust.
> > Everything collectible that I can
> > think of is sold by graded condition. We need to start becoming more
> > critically descriptive in our marketing.
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Mile High Meteorites
Lakewood, CO 80215-9293
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