A single 700 gram stone was found after falling on the Ölgiy Plain in Mongolia. The Jalanash fall was witnessed on August 15, 1990. Full mineralogical descriptions of Jalanash have not appeared in ready available publications, but microstructures in Jalanash pigeonite have been the object of some recent studies of Jalanashs microstructures. Pigeonite is stable at ambient temperature only when cooled very rapidly. Source
Jalanash Bayan-Ölgiy, Mongolia Fell 1990 August 15. Ureilite A 700 g stone was collected after its fall on the plain of Ölgiy in western Mongolia. Classification and analysis reported in Yanai and Byambaa (1996) and Weber and Bischoff (1998): monomict ureilite; olivine, Fa19.3; pyroxene, Fs17.2Wo7.8; shock stage S3; similar to Asuka 881931; bulk composition in Yanai et al. (1995). Specimens: main mass, unknown; type specimen, Mün. Source