Nr. 102440562

Nicht mehr verfügbar
NWA 6704 Ungruppierte Achondrite - 31.3 g - (1)
Auktion beendet
Vor 12 Wochen

NWA 6704 Ungruppierte Achondrite - 31.3 g - (1)

NWA 6704 is a highly studied ungrouped achondrite with distinctive yellow-green interior. It it one of only a few achondrites that show strong relationship to Carbonaceous Chondrites rather than ordinary chondrites. The full description of the meteorite from Metbul appear below. Meteorite will be shipped from Switzerland Writeup from MB 99: Northwest Africa 6704 (NWA 6704) Algeria Purchased: Jan-May 2011 Classification: Ungrouped achondrite History: A single, dense, yellowish-green stone was found in pieces in Algeria, and was purchased in February 2011 at the Tucson Gem and Mineral Show and over subsequent weeks from Moroccan dealers by Greg Hupé. Physical characteristics: The reassembled 42 pieces (plus some granular debris) fit together as a single ovoid mass (8387 g) with rounded, shiny exterior surfaces and small patches of remnant black fusion crust. The very fresh interior is mostly pale yellowish green with sporadic darker brownish grains and sparsely distributed tiny grains of opaque oxide and silvery metal. Petrography: (A. Irving and S. Kuehner, UWS): Overall medium grained with an igneous cumulate texture. Small grains of olivine (0.5-0.8 mm) and chromite (0.1-0.6 mm) enclosed within large (to 4 mm) orthopyroxene oikocrysts, which are in turn surrounded by large optically continuous, intercumulus grains of untwinned albite and mm awaruite. The silicates contain curvilinear trains of tiny rounded inclusions (2-20 μm), which appear on polished surfaces to be empty bubbles with smooth rounded walls. Geochemistry: Olivine (Fa51.6-53.2; FeO/MnO=120-140; NiO=0.9-1.0 wt.%), orthopyroxene (Fs41.6-42.4Wo2.8-3.6, FeO/MnO=81-82; Cr2O3=0.3 wt.%), plagioclase (Ab92-93An4-3Or4). Oxygen isotopes (R. Tanaka, OkaU): replicate analyses of acid-washed material by laser fluorination gave: δ17O 1.015, 0.880; δ18O 3.922, 3.613; Δ17O -1.048, -1.020 per mil. Classification: Achondrite (ungrouped). This specimen is unlike other achondrites in its combined features: relatively ferroan mafic silicate minerals with elevated FeO/MnO ratios and anomalous Ni contents, extremely sodic plagioclase, very Ni-rich metal, and oxygen isotopic composition that plots within the field for acapulcoites-lodranites. Weathering is low and limited to minor coatings of pale orange desert dust on broken surfaces. Unshocked. Specimens: A total of 20.5 g of type material and two polished thin sections are on deposit at UWS. The remaining material is held by GHupé.

Nr. 102440562

Nicht mehr verfügbar
NWA 6704 Ungruppierte Achondrite - 31.3 g - (1)

NWA 6704 Ungruppierte Achondrite - 31.3 g - (1)

NWA 6704 is a highly studied ungrouped achondrite with distinctive yellow-green interior. It it one of only a few achondrites that show strong relationship to Carbonaceous Chondrites rather than ordinary chondrites.

The full description of the meteorite from Metbul appear below.

Meteorite will be shipped from Switzerland

Writeup from MB 99:
Northwest Africa 6704 (NWA 6704)

Algeria

Purchased: Jan-May 2011

Classification: Ungrouped achondrite

History: A single, dense, yellowish-green stone was found in pieces in Algeria, and was purchased in February 2011 at the Tucson Gem and Mineral Show and over subsequent weeks from Moroccan dealers by Greg Hupé.

Physical characteristics: The reassembled 42 pieces (plus some granular debris) fit together as a single ovoid mass (8387 g) with rounded, shiny exterior surfaces and small patches of remnant black fusion crust. The very fresh interior is mostly pale yellowish green with sporadic darker brownish grains and sparsely distributed tiny grains of opaque oxide and silvery metal.

Petrography: (A. Irving and S. Kuehner, UWS): Overall medium grained with an igneous cumulate texture. Small grains of olivine (0.5-0.8 mm) and chromite (0.1-0.6 mm) enclosed within large (to 4 mm) orthopyroxene oikocrysts, which are in turn surrounded by large optically continuous, intercumulus grains of untwinned albite and mm awaruite. The silicates contain curvilinear trains of tiny rounded inclusions (2-20 μm), which appear on polished surfaces to be empty bubbles with smooth rounded walls.

Geochemistry: Olivine (Fa51.6-53.2; FeO/MnO=120-140; NiO=0.9-1.0 wt.%), orthopyroxene (Fs41.6-42.4Wo2.8-3.6, FeO/MnO=81-82; Cr2O3=0.3 wt.%), plagioclase (Ab92-93An4-3Or4). Oxygen isotopes (R. Tanaka, OkaU): replicate analyses of acid-washed material by laser fluorination gave: δ17O 1.015, 0.880; δ18O 3.922, 3.613; Δ17O -1.048, -1.020 per mil.

Classification: Achondrite (ungrouped). This specimen is unlike other achondrites in its combined features: relatively ferroan mafic silicate minerals with elevated FeO/MnO ratios and anomalous Ni contents, extremely sodic plagioclase, very Ni-rich metal, and oxygen isotopic composition that plots within the field for acapulcoites-lodranites. Weathering is low and limited to minor coatings of pale orange desert dust on broken surfaces. Unshocked.

Specimens: A total of 20.5 g of type material and two polished thin sections are on deposit at UWS. The remaining material is held by GHupé.

Auktion beendet
Francesco Moser
Experte
Schätzung  € 1.100 - € 1.300

Ähnliche Objekte

Für Sie aus der Kategorie

Mineralien und Meteoriten

Suchalarm einrichten
Richten Sie einen Suchalarm ein, um benachrichtigt zu werden, sobald neue passende Objekte verfügbar sind.

Dieses Objekt wurde vorgestellt in:

                                        
                                                                                                    
                    
                                        
                                                                                                    
                    
                                        
                                                                                                    
                    
                                        
                                                                                                    
                    

So kaufen Sie auf Catawiki

Mehr zum Käuferschutz erfahren

      1. Etwas Besonderes entdecken

      Entdecken Sie in unseren Auktionen Tausende von besonderen Objekten, die von Experten ausgewählt wurden. Sehen Sie sich die Fotos, die ausführliche Beschreibung und den Schätzwert der besonderen Objekte an, die Sie interessieren. 

      2. Höchstgebot abgeben

      Finden Sie etwas, das Sie begeistert, und geben Sie das Höchstgebot ab. Sie können die Auktion bis zum Schluss mitverfolgen oder unser System für Sie bieten lassen. Dazu müssen Sie einfach nur den Maximalbetrag eingeben, den Sie für das jeweilige Objekt ausgeben möchten. 

      3. Sichere Zahlung durchführen

      Bezahlen Sie Ihr besonderes Objekt und wir verwahren Ihre Zahlung, bis Ihr Objekt unversehrt bei Ihnen angekommen ist. Wir wickeln alle Transaktionen mit einem zuverlässigen und sicheren Zahlungssystem ab. 

Haben Sie etwas Ähnliches zu verkaufen?

Unabhängig davon, ob Online-Auktionen Neuland für Sie sind oder ob Sie gewerblich verkaufen – wir helfen Ihnen, mehr mit Ihren besonderen Objekten zu verdienen.

Objekt verkaufen