We address the problem of observed charmonium decays which should be f
orbidden in perturbative QCD. We examine the model in which these deca
ys proceed through a gluonic component of the J/psi and the eta(c), ar
ising from a mixing of (ccBAR) and glueball states. We give some bound
s on the values of the mixing angles and propose the study of the ppBA
R-->phiphi reaction at square-root s congruent-to 3 GeV as an independ
ent test of the model.