Strangelets and their possible astrophysical origin

We discuss the first-order phase transition of QCD at high temperature in the universe and the possible formation of quark-matter lumps through cooling in regions of increased pressure. We show tha similarity of results using confinement and breaking of chiral symmetry. The inclusion of strange matter may give stability to small drops, or strangelets, in the colour-flavour locked phase possibly achieved in neutron stars that could reach a high-altitude observatory like that of Chacaltaya as primary cosmic rays.