We study a concentration phenomenon in a gossip model that evolves over a stochastic block model (SBM) with two communities. We study the conditional mean of the stationary distribution of the gossip model over the SBM, and show that it is close to the mean of the stationary distribution of the gossip model over an averaged graph, with high probability. As a consequence, regular (non-stubborn) agents in the same community of the gossip model over the SBM have stationary states with similar expectations. The results show that it is possible to use the gossip model over the averaged graph to approximate and analyze the gossip model over the SBM, and establish a correspondence between agent states and community structure of a network. We present numerical simulations to illustrate the results.