Ions produced by the 1064 nm Nd: YAG laser ablation of various Si-C samples include mixed silicon carbon (Si(x)C(y)) cluster ions of low molecular mass. Unique Si(x)C(y) cluster ion distributions are observed. A charge state effect for Si(x)C(y) clusters is evident from differences between the respectively charged distributions. This may be accounted for by either differing energetics and/or differing formation mechanisms for positive and negative Si(x)C(y) cluster ions. Several specific Si(x)C(y) clusters of probable high stability consistently dominate the mass spectra. The chemistry of the more abundant Si(x)C(y) ions was probed by collision-induced dissociation and ion-molecule reactivity experiments. Similar Si(x)C(y)+. dissociation results in the common loss of an Si ion. Parent Si(x)C(y) ion and small neutral reagent reactants give rise to oxidation, addition and exchange reactions.