The Russian Orthodox Church is very into icons. They are believed to be windows into heaven, a link to the divine on the mortal plane. The mosaics are unique in the way they seem dematerialized and abstract.The figures are often painted onto a golden background. It makes the image seem to flicker in the candle light. Halos are also commonly used in Orthodox icons. Also known as nimbus or auroras, they surround saints, prophets, Jesus and Mother Mary. One of the reasons icons are so useful is they were used to teach the illiterate. Paintings, mosaics, and statues could communicate the stories of the bible quite well to those who couldn't read it for themselves.