We describe the properties of six-jet events,
with six-jet mass exceeding 520 GeV/$c^2$,
produced at the Fermilab proton-antiproton collider
operating at a center-of-mass energy of 1.8~TeV.
Observed distributions for a set of 20 multijet variables are compared
with predictions from the HERWIG QCD parton shower Monte Carlo program,
the NJETS leading order QCD matrix element Monte Carlo program,
and a phase-space model in which six-jet events are distributed uniformly
over the kinematically allowed region of the six-body phase space.
In general the QCD predictions provide a good description of the
observed six-jet distributions.