Do Russian Orthodox Wear Skull Caps?

It is worn by men in Orthodox communities at all times. Among non-Orthodox communities, those who wear them customarily do so only during prayer, while attending a synagogue, or in other rituals.

Do Orthodox Christians wear head coverings?

In U.S. churches they are less commonly worn. Eastern Orthodox nuns wear a head covering called an apostolnik, which is worn at all times, and is the only part of the monastic habit which distinguishes them from Eastern Orthodox monks.

What do Orthodox priests wear on their heads?

A kalimavkion (Greek: καλυμμαύχιον), kalymmavchi (καλυμμαύχι), or, by metathesis of the word's internal syllables, kamilavka (Russian: камилавка), is a clerical headdress worn by Orthodox Christian and Eastern Catholic monks (in which case it is black) or awarded to clergy (in which case it may be red or purple).