Coptic Church

A six-pointed star on the upper right side of this decoration which is in the Coptic "Hanging Church" in Old Cairo, Egypt . It is called el-Muallaqa in Arabic, and is dedicated to St. Mary.
Picture is courtesy of "phool 4 XC" who published it on Flickr.
This is the first time I stumble upon a Coptic six-pointed star.

From:

The Mystery Of The Menorah And The Star Richard A. Freund University of Hartford in

Nationalism, Zionism and ethnic mobilization of the Jews in 1900 and beyond‏ ed. Michael Berkowitz, 2004 ISBN 9004131841 ‏:

Coptic Christianity also picked up the symbol and used it on stamps with a cross in the center, a rosette in the center, and with a series of triangles in and around the points of the hexagram