Search for Strange Matter by Heavy Ion Activation
  We present the results of an experimental search for stable strange matter using the heavy ion activation technique. We studied samples of a meteorite, terrestrial nickel ore, and lunar soil. Our search improved the existing experimental limit on the strange matter content in normal matter by 2 to 3 orders of magnitude, and allowed us to probe for the first time the flux of low mass strangelets on the lunar surface. 
M.C. Perillo Isaac, Y.D. Chan, R. Clark, M.A. Deleplanque, M.R.   Dragowsky, P. Fallon, I.D. Goldman, R-M. Larimer, I.Y. Lee...