  Strange quark matter is a postulated state which may be the true ground state
of cold hadronic matter. Physicists have been searching for strange quark
matter in the last several decades but found no definite evidence of its
existence. In our experiment, we used the Yale tandem accelerator as a mass
spectrometer to identify possible stable strangelets (small chunks of strange
quark matter) in lunar soil. The search covers the mass range from A=42 to A=70
amu for nuclear charges 6, 8, and 9. No strangelets are found at sensitivity
levels down to $\sim10^{-17}$. The implied limit on strangelet flux in cosmic
rays is the most sensitive to date for the covered mass range.
