[meteorite-list] The Perils of Type Collecting - A Guide

From: cdtucson at cox.net <*cdtucson_at_meteoritecentral.com*> Date: Wed, 3 Mar 2010 19:12:20 -0500 Message-ID: <20100303191220.QIU11.920303.imail_at_fed1rmwml40> · cdtucson_at_meteoritecentral.com

--
Carl or Debbie Esparza
Meteoritemax
---- Richard Kowalski <damoclid at yahoo.com> wrote: 
> Thanks a lot Mike.
> 
> I thought I had pretty much completed my type set a few months ago, but now I see that I'm missed a few gradations that maybe I should pay attention to.
> 
> I think, for budgetary and sanity sake, I'll have to be selective in how fine my divisions are than to try to get every sub-type you mention!
> 
> --
> Richard Kowalski
> Full Moon Photography
> IMCA #1081
> 
> 
> --- On Wed, 3/3/10, Galactic Stone & Ironworks <meteoritemike at gmail.com> wrote:
> 
> > From: Galactic Stone & Ironworks <meteoritemike at gmail.com>
> > Subject: [meteorite-list] The Perils of Type Collecting - A Guide
> > To: "Meteorite List" <meteorite-list at meteoritecentral.com>
> > Date: Wednesday, March 3, 2010, 4:18 PM
> > Greetings Listees and fellow
> > collectors,
> > 
> > To the veteran collector, there will be little of interest
> > in this
> > post.? This post is directed at the silent newbie or
> > beginner lurkers
> > who are sorting through this List and trying to find their
> > way around
> > the world of collecting meteorites.
> > 
> > Many new collectors often want one of each type of
> > meteorite.? Many
> > veteran collectors abandon this pursuit because the task is
> > quite
> > daunting.???So when you hear talk about
> > "type collecting", or building
> > a "type collection", what exactly does that mean?? I
> > hope the
> > following brief article will answer those questions, or at
> > least point
> > the reader in the right general direction.? Note, I
> > gleaned much of
> > this type information from David Weir's authoritative
> > website
> > "Meteorite Studies" and from the Meteoritical
> > Bulletin.? I do not
> > claim that this list is 100% complete or without error, so
> > if the
> > reader spots an error or omission, please reply and correct
> > it.
> > 
> > -----
> > 
> > The Perils of Type Collecting ........
> > 
> > I started out collecting meteorites with a small sample of
> > NWA 4293 -
> > an ordinary high iron chondrite of the H6 type. It was
> > about the size
> > of a dog-food kibble and it looked like one. But I was
> > instantly
> > hooked, and I wanted to have one each of the different
> > types of
> > meteorite. This is known as "type collecting" or building a
> > "type
> > collection".
> > 
> > The danger of type collecting (besides the damage to one's
> > checking
> > account) is that the various petrologic types are
> > subdivided into
> > various grades according to metamorphism.
> > 
> > For example, take the H chondrite group that my NWA 4293
> > sample belonged to.
> > 
> > There are H3 chondrites, H4 chondrites, H5 chondrites, and
> > H6
> > chondrites. Did I really need one each of these subtypes?
> > Well, it
> > depends on how deep a collector wants to go into the rabbit
> > hole.
> > There are distinct differences between the various H types.
> > The number
> > attached to each is more than just a simple weathering
> > grade or shock
> > grade. It represents a progession in the H-chondrite family
> > from least
> > altered to most altered. H3 chondrites are loaded with
> > chondrules, H4
> > have some chondrules, H5 has few chondrules, and H6 has
> > virtually no
> > visible chondrules. A new grade of H7 has been added as
> > well. So, a
> > collector could simply have a single Hx chondrite and say
> > that the
> > H-chondrites are represented. Or, the collector could have
> > one each of
> > the different subtypes from 3 to 7.
> > 
> > Another peril is the changing of nomenclature. For example,
> > the
> > K-subgroup of carbonaceous chondrites was only recognized
> > and
> > designated in 1990. Up until then, Karoonda was considered
> > a CV4
> > meteorite of the Vigarano family. Now Karoonda is
> > recognized as
> > distinctly different type of carbonaceous chondrite, so it
> > was made
> > into it's own group. Now we have CK4, CK5, and CK6
> > meteorites - all
> > represent a progression in metamorphism and have visible
> > (and
> > chemical) differences from other grades. There are standout
> > members of
> > each subgroup, so where does one draw the line? Should the
> > collector
> > acquire a sample of Karoonda and be done with it? Or should
> > the
> > collector go out and track down CK4, CK5 and CK6
> > meteorites? Again, it
> > depends on how extensive and exhaustive a collector wants
> > to be with
> > their type collection. Budget will also play a role as
> > well, because
> > an exhaustive type collection is a daunting project.
> > 
> > Lastly, one must consider the ungrouped meteorites. These
> > are oddball
> > meteorites that do not neatly fit into the pre-existing
> > meteorite
> > types. There are ungrouped chondrites, ungrouped
> > achondrites, and
> > ungrouped irons. No type collection can overlook these
> > meteorites
> > because some of them are types unto themselves with unique
> > qualities.
> > 
> > For those who want to build a definitive and complete type
> > collection,
> > here is a list of every known type and subtype of
> > meteorite. This list
> > was culled from other sources, including David Weir's
> > authoritative
> > "Meteorite Studies" website linked at the end of this
> > post.
> > 
> > Carbonaceous Chondrites :
> > 
> > CI (Ivuna)
> > CM1 (Murchison)
> > CM2 (subdivided into CM2.0 to CM2.6)
> > CM3
> > CO3 (Ornans) (subdivided into CO3.03 to CO3.7)
> > CV (Vigarano) (also CV2 and CV3)
> > CK (Karoonda) (CK4, CK5, CK6)
> > CR (Renazzo) (CR1, CR2, CR3)
> > CB (Bencubbin)
> > CH
> > CR ungrouped
> > C4 ungrouped
> > C ungrouped (Tagish Lake, others)
> > 
> > 
> > Ordinary Chondrites :
> > 
> > Rumuruti R3 (subdivided into R3.5-6 to R3.9)
> > R4
> > R5
> > R6
> > 
> > LL (subdivided into LL3.0 to LL3.9)
> > LL4
> > LL5
> > LL5/6
> > LL6
> > LL6/7
> > LL7
> > LL impact melt
> > 
> > LL transitional (L/LL3 to L/LL6)
> > L (subdivided into L3.0 to L3.9)
> > L4
> > L5
> > L6
> > L6/7
> > L7
> > L impact melt
> > 
> > H/L transitional (H/L3 to H/L6 IMB, H/L3.6 to H/L3-4)
> > H (subdivided into H3.0 to H3.9)
> > H4
> > H5
> > H6
> > H7
> > H impact melt
> > ungrouped ordinary chondrites
> > 
> > 
> > Enstatite Chondrites :
> > 
> > EL (EL3 to EL7)
> > EL impact melt
> > EH/L
> > EH (EH3 to EH7)
> > EH impact melt
> > ungrouped enstatite chondrites
> > 
> > K (Kakangari)
> > 
> > Meta-chondrites (M-CV, M-CR, M-H, M-LL)
> > 
> > 
> > Primitive Chondrites :
> > 
> > Acapulcoite
> > Lodranite
> > Winonaites
> > ungrouped primitive chondrites
> > 
> > 
> > Achondrites :
> > 
> > Howardite (subdivided into fragmental breccia and regolith
> > breccia)
> > Eucrite (monomict and polymict with each having
> > subclasses)
> > Diogenite (monomict and polymict)
> > Olivine Diogenite
> > Dunite
> > Ureilite (monomict and polymict)
> > 
> > 
> > Martian achondrites :
> > 
> > Shergottite
> > Pyroxene-phyric basaltic shergottite
> > Olivine-phyric basaltic shergottite
> > Olivine-orthopyroxene-phyric basaltic shergottite
> > Pyroxene-peridotitic (Wehrlitic) shergottite
> > Lherzolitic shergottite
> > Diabasic shergottite
> > 
> > Nakhlite
> > Chassignite
> > Orthopyroxenite (ALH 84001)
> > 
> > 
> > Lunar Achondrites :
> > 
> > Feldspathic breccias
> > Regolith breccia
> > Fragmental breccia
> > Impact melt breccia
> > Granulitic breccia
> > Mafic-rich
> > Thorium-rich
> > KREEP-rich
> > 
> > Mingled Breccia
> > Mare Basalt
> > 
> > 
> > Other Achondrites :
> > 
> > Angrites (Plutonic and Basaltic)
> > Brachinite
> > Aubrite
> > ungrouped achondrites (Ibitira, Pasamonte, etc)
> > 
> > 
> > Stony-Irons :
> > 
> > Mesosiderites (1A,1B,2A,2B,2C,3A,3B,4A,4B)
> > ungrouped mesosiderites
> > 
> > Pallasites (Main Group, Eagle Station group, Pyroxene
> > group)
> > Pallasite-am (anomalous, PMG-am, PMG-as)
> > ungrouped pallasites
> > 
> > 
> > Iron meteorites :
> > 
> > Note, iron meteorites are a can of worms. I will only focus
> > on the
> > main chemical groups, and not the various grouplets and
> > sub-types of
> > each main chemical group.? Also note that many of
> > these types include
> > silicated varities.? Listing all of the known
> > sub-types of irons would
> > require a LONG list resembling a flow-chart.
> > 
> > IAB
> > IC
> > IIAB
> > IIC
> > IID
> > IIE
> > IIF
> > IIG
> > IIIAB
> > IIIE
> > IIIF
> > IVA
> > IVB
> > ungrouped irons
> > 
> > I think that is all of them - as currently recognized by
> > the
> > Meteoritical Society Nomenclature Committee. If anyone can
> > think of
> > some I missed, please add them to this list.
> > 
> > David Weir's Meteorite Studies website - http://www.meteoritestudies.com/
> > 
> > Best regards and happy collecting!
> > 
> > MikeG
> > 
> > 
> > -- 
> > ------------------------------------------------------------
> > Mike Gilmer - Galactic Stone & Ironworks Meteorites
> > http://www.galactic-stone.com
> > http://www.facebook.com/galacticstone
> > ------------------------------------------------------------
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> > 
> 
> 
>       
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