Watonga        35°50±3’N, 98°24±3’W

Blaine County, Oklahoma, USA

Found: 1950-1960

Classification: Ordinary chondrite (LL3.1)

History: The seller discovered the stone in the weight box of a disk plow used by his father in the 1950s-1960s. He believes his father found the stone while plowing and placed it in the weight box. The stone possesses a nick where it was likely hit by the plow. The stone was unlike others in the weight box, which prompted the seller to save it for several years until finally bringing it forward for identification.

Physical characteristics: A single 21.0 × 17.1 × 10.8 cm mass weighing 5025 g. Black fusion crust up to ~0.7 mm thick  covers ~70%. The surface is otherwise smooth, dark brown, rust-marked, and pitted in places where inclusions (not chondrules) weathered out. White inclusions and light beige inclusions up to 2.5 cm are visible on the surface, though none are present in the few cuts made from the stone. The stone is highly oriented, possessing the smooth, ballistic shape of a flattened nose cone, and a sharply flat truncation on the bottom of that shape.

Petrography: (D. London, UOkla): PP/CP chondrules are round, sharp in definition, averaging ~0.8 mm in diameter, and comprising ~60-80 vol% of the stone.

Geochemistry: (D. London and G. B. Morgan VI, UOkla): Olivine; range (64 analyses) is Fa_0.8-42.5, average (sd) Cr₂O₃ content (wt. %) of ferroan grains (9 chondrules) is 0.39 (0.15). Average composition (wt.%) of metal in chondrules is: (1)  Fe-rich,  95.19±1.19 Fe, 3.72±0.79 Ni, 0.36±0.05 Co, 0.13±0.13 Cr, 0.06±0.12 P, and (2) Ni-rich, 51.37±6.34 Fe, 48.17±5.83 Ni, 0.08±0.06 Co, 0.11±0.12 Cr, 0.02±0.02 P. Average composition of metal in matrix is: (1) Fe-rich, 93.57±2.37 Fe, 4.11±0.46 Ni, 1.93±2.37 Co, 0.06±0.06 Cr, 0.04±0.09 P, and (2) Ni-rich, 52.35±3.95 Ni, 46.13±4.04 Fe, 0.90±0.40 Co, 0.02±0.02 Cr, 0.01±0.01 P.

Classification: (D. London and G. B. Morgan VI, UOkla; M. Weisberg, KCCU): LL3.1,S2, W2: classification as LL is based on (1) low modal abundance of metal, 0.05 vol%, as measured by threshold (gray-level bin sorting) of a BSE mosaic that covered 35% (~2 × 0.4 cm) of the surface area of the existing sample; and (2) mean chondrule size of ~ 0.8 mm. Petrographic classification is based on Cr content of high-Fa olivines.