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Allende
This renowned meteorite descended as a shower upon an area of 10 x 50km2; some 3 t of material have been collected since. Allende is the only carbonaceous chondrite available to collectors at an accessible price. Much has been said and even more written on Allende. Allende is often referred to as the Rosetta stone of planetology, for, having arisen from the primal solar nebula, it provides us with most precious insight into the composition of that nebula as well as the conditions under which our solar system formed. A few research results: The protoplanetary nebula was not homogeneous in composition, density and temperature. The krypton, xenon and nitrogen contents of Allende's micro-diamond inclusions present isotope ratios unknown in our solar system. - Which means that those diamonds are of interstellar origin. Allende contains an increased concentration of aluminium-26 decay products, which can only originate from a supernova explosion in our sun's neighbourhood. The shock waves of that explosion may have been the cause of the collapse of the primal solar nebula. Allende contains the famous calcium-aluminium-rich inclusions (CAIs) which are considered to be the very first concrete, and therefore the oldest, matter in our solar system, (Cf. the especially large, whitish spot of irregular shape at the bottom, on the right.) By know, the Allende strewnfield is exhausted, having caused prices to rise in recent years (current average price 7.70$/g). 5.50$/g. Endcut with large
cut surface and some fusion crust Dar al Gani 232
Over the last ten years, systematic searches have been performed in those regions of the Sahara desert which, due to their surface nature, lend themselves to such exploration. Hundreds of new meteorites were discovered which found their way into trade under such names as Sahara, Dar al Gani, Açfer, Hammada al Hamra, Bechar, Tagounite + find number. Those desert meteorites are the cheapest of all, and represent an excellent occasion for the collector to acquire somewhat rarer classes, too, such as the L3 and H3 types. The "Catalogue of Meteorites" (1985) lists only 13 pure, non-antarctic L3s, out of a total of 669 representatives of the L-group. For the H3s, the ratio is 15:681. That's why those unequilibrated chondrites are so high in demand and expensive (for more on that cf. DaG 316): In Nov 99 the non-desert L3s cost 40$/g on average, the desert finds 27$/g. (H3s are considerably cheaper) 9.50$/g. Cut fragment ca. 4cm x 2cm x 1.5cm 22.13g $210 Dar al Gani 316
For desert finds, cf. DaG 232. Most probably, all chondrites were at one stage chondrites of the petrological type 3. In type-3 chondrites the globular silicate inclusions, the so called chondrules, distinguish themselves clearly from the fine-crystalline ground mass (matrix). Those rock masses were probably situated at only a moderate depth inside their body of origin. The smaller asteroids were never heated up to an extent that would have caused them to melt, but the temperatures towards the core incited further crystallisation and crystal growth in the chondritic material, so that the chondrules in type 4 to type 6 present more and more close linkage with the matrix, and that, eventually, in type 6, there are only a few distinctly shaped chondrules left. Furthermore, the type-3 meteorites are unequilibrated, i.e. the minerals of equal chemical composition are present in a conglomerate of different crystal types and their distribution is uneven. In types 4 to 6 those release ions, due to heating, and dissolve. In brief: The type-3 meteorites are those ordinary chondrites which are preserved in the most pristine of conditions. DaG 316 shows shock stage S2 and weathering grade W3. 6.50$/g. Fullslice ca. 7.5cm x 6.5cm x 0.5cm 64.8g $421.20Densmore (1879)
Three fragments, totalling 37.2kg, were found by F.M.Kendrick 5km to the East and 2.4km to the South of Densmore; but it wasn't until 1939 that they were recognized as meteoritic. A fourth piece of 15.4kg was discovered about 1950. Densmore (1879), like most historical finds, is almost unavailable on the market now (I for my part know of a single source only, where it is offered at 4$/g), about 90% being held in state collections, 42kg of that in Washington, U.S. Nat. mus. Densmore has a very beautiful, fresh, dark matrix with tiny little light metal flakes. 3.50$/g. Partslice,
one side polished
Origin and fall of this recent meteorite were for some time shrouded in darkness. In early 1997 nomads sold a fragment in Morocco. They claimed to have found it in Western Algeria after observing a bolide in January 1995. This material became known under the name Hamada du Draa, or, less frequently, Mhamid, after the place where it was sold. Those self-same nomads sold another piece in September, which had allegedly fallen a month before. Upon which, in November, Edwin Thompson found six unweathered stones in Mauretania, most probably at the site of the fall, which were subsequently offered, in parallel to Hamada du Draa, under the denomination El Hammami. By now (Meteoritical Bulletin No.82, 1998) the two are considered to be one and the same. The data, for comparison: Hamada du Draa: olivine, Fa19.2; pyroxene Fs17.4; shock stage S2; type H5/6 El Hammami : Fa18.8; Fs16.7; S2; H5 A further striking feature of both meteorites is that they present metal-rich veining. El Hammami is a truly ubiquitous meteorite, usually available at 1-2$/g. African meteorites, such as Gao or fabulous Zag, not to mention the desert finds, are in general a whole lot cheaper than meteorites of other continents, even though they are in no way inferior to these. Which makes them particularly suitable for the beginning collector. This fragment here (still purchased as Hamada du Draa) has four sides, the largest of them with crust. It is of minor quality, for it shows strong oxidation traces. (In exchange, it costs less than 1$/g). 0.80$/g. Fragment with crust ca. 8.3cm x 7.2cm x 6cm 288g $230.40 Faith
A single, large stone of 105kg was found 37km north-northeast of Faith, and in 1967 was officially recognised as a meteorite. These days, Faith is rarely offered for sale. Small block with dark-brown matrix and clearly recognisable chondrules. 3.75$/g. Partslice
ca. 2.2cm x 1.7cm x 0.8cm 9.1g
$ Forrest (b)
A number of fragments was found 32km to the Southwest of Forrest. Brownish matrix, fresh metal. 2$/g. Cut fragment ca. 6.3cm x 4cm x 1.3cm 36g $72
Gao (Upper Volta)
This meteorite came down 60km to the North of Leo, on the border with Ghana, over a strip of some 10km length, with some stones pertruding the roofs of a number of huts, but fortunately none of the inhabitants were hit. There is some uncertainty as to the total weight of the fall, with indications ranging from 100kg to 500kg. Gao, like most African meteorites, is very cheap; it stems from a witnessed fall and is offered everywhere. The material known as Guenie or Gao-Guenie belongs to the same fall. 1.75$/g. Partslice ca. 10.9cm x 3.7cm x 0.5cm 62g $108.50Juangcheng
After
the apparition of a glaring ball of fire which shed red light on the whole area
and was accompanied by crackling like of fireworks, hundreds of stones rained
down. (One is actually said to have plopped into a soup pot.) A few months
later, Deng Xiaoping died, so that, in retrospect, the fall of this meteorite
was interpreted as a foreboding of his death. This specimen shows a beautiful
fresh black melt crust an has been cut at the spot where it was damaged on
impact, which, Cut
individual with fresh crust.
Kainsaz
This
was a witnessed fall of 15 stones, the largest of which weighed 102.5kg. CO3
meteorites differ from the CV3 types in as much as their chondrules are far
smaller. With its total known weight of 200kg, Kainsaz is the mightiest among
the CO3 meteorites. From this pristine meteorite, I can offer a part slice of
some size. Its hue is a blackish grey with many coloured and a few white
inclusions. Kainsaz is usually offered at 70-75$/g. My price is 45$/g. In Partslice
Kunya-Urgench
As one can tell from the varying place names and types under which this meteorite has shown up and which I have reproduced here, nothing definitive seems to be known about this quite mighty fall, yet. I read that the main mass left behind a 6x4m² hole and that almost all the material was seized by the local authorities. Until half a year ago, Kunya-Urgench was offered rather frequently - today, however, it has disappeared from the market almost completely! And I, too, have only this one piece left. 3.50$/g. Fragment ca. 4.8cm x 3.2cm x 1.5cm 40g $140Marlow
In 1936, a weathered stone of just a few hundred grams was found, whereas the main mass of 100kg wasn't discovered until 1987. Polished cut surfaces with a fresh, elegant black matrix. 2$/g. Cut
fragment, polished
Murchison
There are some 12kg of Murchison available to private collectors. The CM2 types, together with the C1 types, represent the most primitive and pristine matter in our solar system. Murchison also has CAIs (cf. Allende). A very interesting feature about it is its water content (12%) and, first and foremost, the fact that Murchison contains over 100 amino acids, the basic components of biological life. This gave new vitality to the old theory of "lithospanspermism", according to which life was inoculated into the primeval earth (life on earth, however, uses only laevorotatory amino acids whereas Murchison contains neither laevo- nor dextrorotatory ones) and on the occasion of the 1997 San Diego Optics Conference, even the discovery of "fungoid and other possibly biological fossile structures" under the ESEM microscope was claimed. Furthermore, there is some reason to believe that CM2 meteorites stem from comet cores. So let's remember the last two marvellous comets, Hyakutake and Hale-Bopp: Now here you can touch one of these! Very fresh fragment with crust; however, there is a colour mark on the crust. 65$/g. Fragment with fusion crust ca. 2.5cm x 2.1cm x 0.9cm 7.0g $455 Pultusk
The
tremendous shower of Pultusk is the most famous meteorite fall of the 19th
century. On the evening of Jan 30th 1868, between Pultusk and Ostrolenka on the
Narew, no fewer than 180 000 stones rained down on an area of 1.5 x 8km2; only
some 200 of these weighed more than 1kg. The trajectory of the fireball, which
entered at an angle of 44°, could be traced over a distance of 182km. The total
mass of the fall has been estimated at far beyond 2t, nevertheless only slightly
under 250kg have been preserved in the collections of this world of ou Individual,
almost fully crusted
St. Lawrence
Amphoterites are ordinary chondrites, which differ from the L and H classes in as much as they present a lower iron content of only 18.5-21.5%, only 0.5-4% of which is still present in the form of metallic iron (LL = Low iron, Low metal). This one here is an ashlar (not unlike the ones that swirl around Jupiter in the Odyssey movies), with one side polished. The high price is justified due to the somewhat rarer class, but mainly due to the low total known weight of the find. I don't thing much about people going about shouting "Last chance to buy!", but if this item fits into your collection area or if, quite simply, you fancy owning a meteorite hardly anybody else has, you should have an eye on this one. 11$/g. Polished Partslice ca. 3.1cm x 2.2cm x 1cm 22.08g $242.90 Saratov
Saratov is a famous and well-documented meteorite from a spectacular fall (with fireball, explosions and the whole paraphernalia… - the largest piece weighed 160kg). Saratov material is known for its exceptionally large chondrules - some inclusions measure almost one cm in diameter! Saratov is of very loose and crumbly consistency, so that it can hardly be sawed into stable thin slices. The slice offered here shows the typical rust halos that inevitably form around the chondrules within a short time after cutting. Despite its peculiarities, Saratov can be offered considerably cheaper than American L4s. 1.70$/g. Partslice ca.10.5cm x 7.5cm x 1.4cm 276g $Tsarev
Even though the fall of Tsarev on December 6th 1922 was probably witnessed, the meteorite wasn't discovered until 1968, and it took another 11 years for the discovered masses to be recognised as meteoritic. All in all 44 chunks, the largest of which weighed 284kg, were discovered, the total weight being 1225kg. This makes Tsarev the third largest stone meteorite after Allende and Jilin (there isn't much left of Pultusk, and the Tkw of Kunya-Urgench has yet to be determined), so that it should be present in every collection. However, there isn't much of Tsarev on the market. Tsarev is heavily shocked material with a black matrix. 2.50$/g. Fullslice, polished ca. 8.3cm x 5.7cm x 0.6cm 78g $ |
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