— An impressive daylight fireball was observed from Spain, Portugal, and the south of France at 16h46m45s UTC on January 4, 2004. The meteoroid penetrated into the atmosphere, generating shock waves that reached the ground and produced audible booms. The associated airwave was recorded at a seismic station located 90 km north of the fireball trajectory in Spain, and at an infrasound station in France located 750 km north‐east of the fireball. The absolute magnitude of the bolide has been determined to be −18 ± 1 from a casual video record. The energy released in the atmosphere determined from photometric, seismic, and infrasound data was about 0.02 kilotons (kt). A massive fragmentation occurred at a height of 28 ± 0.2 km, resulting in a meteorite strewn field of 20 × 6 km. The first meteorite specimen was found on January 11, 2004, near the village of Villalbeto de la Peña, in northern Palencia (Spain). To date, about 4.6 kg of meteorite mass have been recovered during several recovery campaigns. The meteorite is a moderately shocked (S4) L6 ordinary chondrite with a cosmic‐ray‐exposure age of 48 ± 5 Ma. Radioisotope analysis shows that the original body had a mass of 760 ± 150 kg, which is in agreement with the estimated mass obtained from photometric and seismic measurements.

Grinding and milling processes lower the intensity of the ultraviolet emission band of alkali feldspars. The luminescence spectra of aliquots of natural transparent adularia from Saint Gothard, Switzerland, that were crushed at different energies, show the irreversible collapse of the UV 290 nm peak. Simultaneously, the 390 nm blue emission increases in accordance with the milling treatment, which reduces the presence of ionic charge compensators (Na⁺) and sensitizes the structure (producing [AlO₄]° centers). The annihilation of the 290 nm UV peak by crushing could be linked with cracks-strain-exsolution features of the lattice of adularia. For this reason, the use of this 290 nm peak and energetic milling treatments in dating and dosimetric routines, should be rejected.