Northwest Africa 16209 (NWA 16209)

(Northwest Africa)

Purchased: Dec 2021

Classification: Iron meteorite (IIIAB)

History: Seventeen pieces with a total mass of 9616 g were purchased by Mr. Jasper Spencer from a Moroccan dealer in December 2021 via Facebook Messenger; the largest piece is 2051 g. Mr. Spencer was told that this material was found in Algeria in 2021. According to Mr. Spencer, some of the seventeen pieces are "flight-shaped." Mr. Spencer donated two pieces (294.1 and 204.7 g) to Cascadia.

Physical characteristics: Physical Characteristics: The exteriors of both pieces donated to Cascadia are brown with orange-red patches. Both pieces have remnant fusion crust on one side, with poorly developed regmaglypts. The opposite sides of both pieces show parallel flat steps that represent kamacite lamellae. On one sample, two steps can be seen to have triangular sides; on the other sample, three parallel steps are partially detached from the main mass.

Petrography: (A. Ruzicka and M. Hutson, Cascadia): Parallel kamacite plates in hand specimen were measured to have a band width of approximately 0.7 to 1 mm. The cut face shows metal with minor rust filling irregular fractures.

Geochemistry: (C. Herd, P. Hill, and S. DuFrane, UAb): ICP-MS data was obtained on a mass of 0.1003 grams of the meteorite, using a sample of North Chile (Filomena) as a standard. Co=0.459, Ni=6.99 (both wt%); Cu=158, Ga=18.8, Ge=36.8, Ru=12.7, Pd=3.30, W=1.87, Re=1.46; Os=20.1, Ir=13.1, Pt=15.9, Au=0.695 (all ppm).

Classification: (M. Hutson and A. Ruzicka, Cascadia; C. Herd, UAlb): IIIAB iron, medium octahedrite. Ni may be low in part due to analytical uncertainty, but the composition is consistent with IIIAB for other reported elements and this meteorite may constitute a low Ni-high Ir member of IIIAB.

Specimens: Cascadia holds 491.6 g in three pieces; Mr. Jasper Spencer holds the main mass.