40Ar/39Ar dating of yimengite from the Turkey Well kimberlite, Australia. The oldest and the rarest. - Kiviets, G.; Phillips, D.; Shee, S.R.; Vercoe, S.C.; Barton, E.S.; Smith, C.B.; Fourie, L.F. (International Kimberlite Conference: Extended Abstracts, 1998)