[Campion]

Orthodox were persecuted by Russian Communists.

And the Orthodox church was extensively infiltrated by the KGB. The Russian Orthodox church has pretty much always been an arm of the government.

[Yardstick]

Orthodox clergy have beards and often wear black; Catholic clergy are clean shaven and often wear white.

Orthodox iconography is more notional with less realism than Catholic iconography.

Orthodox liturgy is sung without instruments.

Orthodox communion has pieces of bread versus Catholic wafers.