Nasza kolekcja meteorytów

Oum Rokba

Chondryt zwyczajny H5

Zakupiony z Michael Farmer Collection, Maj 2007

#051

Thuathe

Chondryt zwyczajny H4/5

Zakupiony z Hupe Collection, Maj 2007

#052

Zag

Chondryt zwyczajny H3-6, S3, W0

Zakupiony z Hupe Collection, Maj 2007

#053

NWA 2871

Prymitywny achondryt, Akapulkoit (ACAP) W3

Zakupiony z kolekcji Jensen Meteorites, czerwiec 2007

#054

Santa Vitoria do Palmar

Chondryt zwyczajny L3, S4, W2

Zakupiony z kolekcji Jensen Meteorites, czerwiec 2007

#055

Mount Egerton

Achondryt przekształcony, Aubryt (AUB-Anom)

Zakupiony z kolekcji Jensen Meteorites, czerwiec 2007

#056

Vaca Muerta

Mezosyderyt A1

Zakupiony z kolekcji Jensen Meteorites, czerwiec 2007

#057

Northwest Africa (NWA) 2625

Achondryt przekształcony - Ureilit (URE)

znaleziony w sierpniu 2004 roku waga: endcut, 0.5 g
wymiary: 23 x 7 x 3 mm
TKW: 305 gr.
Ważšcy 305 gramów całkowity meteoryt został zakupiony w sierpniu 2004 roku w Erfoud w Maroku.
Opis i klasyfikacja (J. Wittke and T. Bunch, NAU): medium- to coarse-grained (<4 mm), typical ureilite with pronounced preferred orientation of silicates, which are mostly elongated with curvilinear morphology. Pigeonite shows well-defined twinning; graphite and carbonaceous-metal-silicate-masses tend to cross trend the lineation direction with some small masses poikilitically enclosed by large pigeonite. The degree of olivine–pigeonite reduction is low to moderate. Olivine cores, Fa20.3 (Cr2O3 = 0.72 wt. %), rims are Fa8-10.8 (Cr2O3 = 0.53 wt. %); pigeonite, Fs17.4Wo7.6 (Cr2O3 up to 1.56 wt. %). Weathering is low grade and the shock level is S2.
Specimens:

• type specimen, 22.2 g, NAU;
• main mass, Hupé.

Zakupiony z kolekcji Hupé, lipiec 2007

#058

Northwest Africa (NWA) 998

Achondryt pochodzenia marsjańskiego - Nakhlit ortopyroksenowy

znaleziony w sierpniu 2001 roku waga: fragment 0.012 g
wymiary: mikro mm
TKW: 456 gr.
A. and G. Hupé (Hupé) purchased, from dealers at the Tucson Gem and Mineral Show in 2002 February, the main mass from a 456 g stone that had been acquired at an unspecified site in western Algeria or eastern Morocco in 2001 September. Dimensions before cutting: 72 mm by 65 mm by 48 mm. Classification and mineralogy (A. Irving and S. Kuehner, UWS): a friable, dark green rock with minor orange-brown alteration products that probably are of pre-terrestrial origin. It is composed mainly of subhedral, olive-green, complexly zoned subcalcic augite (Fs22Wo39) with subordinate yellow olivine (Fa64), orthopyroxene (Fs49Wo4), interstitial plagioclase (Ab61Or4 containing 0.1 wt% SrO, and exhibiting normal birefringence), titanomagnetite, chlorapatite and pyrrhotite. The overall texture is that of a hypabyssal, adcumulate igneous rock, and the apparent crystallization sequence is olivine, orthopyroxene, titanomagnetite, augite, apatite, plagioclase. There is a weak preferred orientation of prismatic pyroxene crystals, many of which have very distinctive zoning, with cores of augite surrounded by irregular, inverted pigeonite rims (now consisting of orthopyroxene with fine augite lamellae). Trains of tiny melt inclusions are present along healed fractures within pyroxene; microprobe study confirms that most of these are K-Na-Al-bearing silicate glass, but some are intergrowths of glass and Fe-bearing carbonate, which may represent quenched immiscible silicate-carbonate liquids. Symplectitic intergrowths of titanomagnetite and low-Ca pyroxene are present at grain boundaries between large, discrete olivine and titanomagnetite grains, but are not present around chromian titanomagnetite inclusions within olivine. These observations suggest that a pre-terrestrial oxidation process produced the symplectites, and involved high temperature, deuteric fluid infiltration along grain boundaries; such fluids also may have produced the irregular pigeonitic rims on augite crystals. Secondary (probably pre-terrestrial) ankeritic carbonate, K-feldspar (some Fe-bearing), serpentine (?), calcite and a Ca sulfate are present on grain boundaries and within cracks in augite.
Oxygen isotope composition (D. Rumble, CIW): replicate analyses of acid-washed augite by laser fluorination gave ?18O = +3.9 ą 0.2‰; ?17O = +2.4 ą 0.1‰; ?17O = +0.30 ą 0.02‰.
12 milligram fragment from NWA 998, a Unique Martian Orthopyroxene-bearing Nakhlite meteorite found in the year 2001. Unique, when describing this meteorite, means it is a one-of-a-kind find. It is different from the other six known nakhlites. This recent Martian meteorite caused quite a stir in the scientific community and is still under intense study. Some of the unique features are it is the first Nakhlite found to contain discrete crystals of Orthopyroxene, the major component of the worlds most famous meteorite ALH 84001. Like ALH 84001, which at one time was sub-classed under Nakhlites, ankertitic and other carbonates have been identified in this meteorite and are pre-terrestrial in origin. These carbonates were deposited in this meteorite when underground water flowed through it beneath the surface of Mars. Another feature is the existence of simplectites, structures that will tell us more about the geology of Mars. These simplectites were formed when a secondary post crystallization event occurred on Mars involving a super heated liquid (water) that chemically altered parts of this rock. If this were not enough, this meteorite contains minerals that were created by extraterrestrial weathering. Several other unique features are being explored and if proven true will lead to a new way of thinking about these rare rocks. Expect to hear a lot more in the news about this most scientifically important find. Specimens:

• type specimen: 20 g, UWS
• type specimen: 20 g, FMNH, and
• type specimen: two polished thin sections, UWS;
• main mass, Hupé.

Zakupiony z kolekcji Hupé, lipiec 2007

#059

Vaca Muerta

Mezosyderyt A1

Zakupiony z kolekcji Rosemary Hackney, Fallen Star Meteorites (IMCA 9479) Tennessee, United States, sierpień 2007

#060