Sayh al Uhaymir 169 (SaU 169) is a 206 gram lunar meteorite found in the Sayh al Uhaymir region of the Sultanate of Oman in January 2002.
This stone is an impact-melt breccia with exceedingly high concentrations of thorium and other incompatible elements; phosphorus, rare-earth elements, and the three most important naturally occurring radioactive elements, potassium, thorium, and uranium, have been segregated in the liquid phase when the lunar minerals crystallized.
It is complete, a light gray-greenish rounded stone, dimensions 70 mm × 43 mm × 40 mm (2.8 in × 1.7 in × 1.6 in) and mass 206 grams (7.3 oz), found on January 16, 2002, in the central desert of Oman at 20° 34.391' N and 57° 19.400' E. According to geologist Edwin Gnos and coworkers, the meteorite's origin can be pinpointed to the vicinity of the Lalande impact crater; isotopic analysis shows a complex history of four distinct lunar impacts: "Crystallization of the impact melt occurred at 3909 ± 13 Ma, followed by exhumation by a second impact at 2800 Ma, which raised the sample to a regolith position at unconstrained depth.
A third impact at 200 Ma moved the material closer to the lunar surface, where it mixed with solar-wind–containing regolith.
It was launched into space by a fourth impact at <0.34 Ma".