Meteoritical Bulletin: Entry for Northwest Africa 6690

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Northwest Africa 6690

Basic information

Name: Northwest Africa 6690
This is an OFFICIAL meteorite name.
Abbreviation: NWA 6690
Observed fall: No
Year found: 2010
Country: (Northwest Africa)
Mass: 88.3 g

Classification
history:

Meteoritical Bulletin:	MB 100	(2012)	Diogenite
Recommended:			Diogenite [explanation]

This is 1 of 545 approved meteorites classified as Diogenite. [show all]
Search for other: Achondrites, Diogenites, and HED achondrites

Comments:

Approved 16 Dec 2011

Writeup

help

Writeup from MB 100:

Northwest Africa 6690 (NWA 6690)

(Northwest Africa)

Purchased: 2010

Classification: HED achondrite (Diogenite)

History: Found by an anonymous person in Western Sahara and purchased 2010 in Erfoud by G. Tomelleri.

Physical characteristics: A single stone of 88.3 g, with no fusion crust.

Petrography: (V. Moggi Cecchi, G. Pratesi, S. Caporali MSP): A monomict coarse-grained orthopyroxenite dominated by orthopyroxene, with subordinate plagioclase and clinopyroxene. Opaque phases are represented by ilmenite and Ti-chromite.

Geochemistry: Low-Ca pyroxene (Fs_31-38Wo_2-3); augite Fs₁₃Wo₄₄; calcic plagioclase (An_86-93), Mg-rich ilmenite (MgO 0.73-0.98 wt%); Ti-rich chromite [Cr/(Cr+Al) = 0.89; Ti = 3.2 wt.%, Mg = 3.0 wt.%]; Oxygen isotopes: (I. Franchi, R. Greenwood, OU) δ¹⁷O = 1.94, δ¹⁸O = 4.19, Δ¹⁷O = -0.24 per mil.

Classification: Achondrite (diogenite) with moderate degree of shock and low degree of weathering.

Specimens: 18.0 g and one thin section are on deposit at MSP (MSP 5156).

Data from:
  MB100
  Table 1
  Line 1486:

Place of purchase:	Erfoud
Date:	P 2010
Mass (g):	88.3
Pieces:	2
Class:	Diogenite
Ferrosilite (mol%):	31-38
Wollastonite (mol%):	2-3
Classifier:	V. Moggi Cecchi, G. Pratesi, S. Caporali, MSP
Type spec mass (g):	18
Type spec location:	MSP
Main mass:	Unknown
Comments:	Submitted by Vanni Moggi Cecchi

Plots:

O isotopes:

Institutions
and collections

MSP: Museo di Scienze Planetarie, Via Galcianese 20/H, 59100 Prato, Italy, Italy; Website (institutional address; updated 22 Oct 2022)
OU: Planetary and Space Sciences Department of Physical Sciences The Open University Walton Hall Milton Keynes MK7 6AA United Kingdom, United Kingdom (institutional address; updated 8 Dec 2011)

Catalogs:

References:

Published in Meteoritical Bulletin, no. 100, MAPS 49, E1-E101 (2014)

Find references in NASA ADS:
Find references in Google Scholar:

Photos:

Credit	Photos
Photos uploaded by members of the Encyclopedia of Meteorites. (Caution, these are of unknown reliability)
Antonello Petriccione

Geography:

Coordinates:

Unknown.

Statistics:
This is 1 of 9914 approved meteorites from (Northwest Africa) (plus 1841 unapproved names)

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