Rumuruti Chondrites

Summary of Rumuruti Characteristics

Minerals and Compositions:

Texture: Chondrules to matrix about equal vol%

Northwest Africa 1906

Found 2003
Rumuruti chondrite (R4)

A 560 g stone was purchased in Rissani in June 2003. Classification and mineralogy (T. Bunch and J. Wittke, NAU): well-defined chondrule outlines with mostly recrystallized matrix and chondrule mesostasis. Olivine, Fa39.4; augite, Fs11Wo46.5; plagioclase, An11Or5; chromite, Cr/(Cr+Fe) = 0.86, Mg/(Mg+Fe) = 0.12; pentlandite, Cr = 2.88 wt. % and merrillite. Shock level, S2, weathering grade, W2. Specimens: type specimen, 26.1 g, NAU; main mass, Farmer.

NWA 1906 © T. E. Bunch 2003

Northwest Africa 2068

Found 2002
Rumuruti chondrite (R3.8)

A 134 g partial stone was purchased in Erfoud, July 2003. Classification and mineralogy (T. Bunch and J. Wittke, NAU): unbrecciated, unequilibrated with little matrix olivine; chondrule mesostasis poorly crystallized. Matrix olivine, Fa39.5 ± 1.8; chondrule and matrix olivine range, Fa15.3-42; orthopyroxene, Fs20.5Wo0.5; poorly crystallized plagioclase, An10.2Or4; pentlandite, Ni = 30.4 wt. %, Co = 1.3 wt. %; chromite, Cr/(Cr+Al) = 0.91. Shock stage, S2: weathering grade, W2. Specimens: 23.2 g. NAU; main mass, Boswell.

NWA 2068 © T. E. Bunch 2004

Northwest Africa 2133

Northwest Africa
Found 2003
Rumuruti chondrite (R4)

A 120 g complete stone was purchased in Rissani in January 2004. Description and classification (J. Wittke and T. Bunch, NAU): well-defined chondrules set in crystallized matrix; numerous pentlandite masses with inclusions of subrounded chromite and olivine. Matrix olivine, Fa39.7-41.9. NiO = 0.05-0.20 wt. %; chromite, Cr/(Cr+Al) = 0.90, Fe/(Fe+Mg) = 0.96, TiO2 = 5.2 wt. %; pentlandite, Ni = 32.4 wt. %, Cr = 0.63 wt. %; plagioclase, An43Or5.2. Shock level, S2 and moderate degree of weathering. Specimens: 21.6 g, NAU; main mass, Boswell.

Northwest Africa 4545

Find: 2006
Rumuruti chondrite (R4)

History and physical characteristics: The meteorite was recovered in the southern Algerian desert in March 2006.and purchased in Munich, Germany in October 2006 by Michael Farmer. The greenish-gray 119 g stone is covered by a very fresh, black fusion crust.
Petrography: (T. Bunch and J. Wittke, NAU) Millimeters wide, cataclastic veins are pervasive throughout the stone. Many small (< 0.2 mm) clusters of pyrrhotite, pentlandite and high silica glass intergrowths occur in the matrix. A few of the smaller chondrules are rimmed by sulfides.
Mineral compositions and geochemistry: Olivine (Fa37.5, FeO/MnO = 77-83 g/g); Ca-pyroxene (Fs11.8Wo44.6); FeS (Ni = 2.32 wt. %); glass (SiO2 = 71.1 wt. %, Al2O3 = 21.4 wt. %, Na2O = 6.4 wt. %; CaO = 1.43 wt. %; FeO = 1.72 wt. %).
Classification: Rumuruti (R4), weathering grade is nearly equivalent to a fresh fall, no visible interior weathering effects observed in microscopic and SEM examination; low shock level.
Type specimen: A 21 g sample is on deposit at NAU. Mr. M. Farmer is the main mass holder.

Other Rumuruti Chondrites

IDLocationDateMass (g) StateFaFsComments
NWA 2069Erfoud, Morocco200344.9S2, W3 39.1-(photograph below)
NWA 2702Erfoud, Morocco2005215S2, W439.5±2.4 -Plag, An44.1Or4.8; chromite, Cr/(Cr+Al)=0.897
NWA 2921Morocco2005195S1, W339.5±1.3- Olivine (FeO/MnO = 72-76 g/g)

Photographs of Rumuruti Chondrites

NWA 2069. Image © T. E. Bunch 2004

NWA 2921. © T. E. Bunch, 2006