ALTAR-STONE.—A solid piece of natural stone, consecrated by a bishop, large enough to hold the Sacred Host and chalice. It is inserted into or placed on the surface of a structure which answers the purpose of an altar, when the whole altar is not consecrated. Sometimes the whole table (mensa) takes the place 4 the smaller altar-stone. It is called a portable altar.
The Catholic Encyclopedia
Altar Stone
1 section
Charles G. Herbermann and others (editors)
Transcribed from a dated scan; artifacts may remain. Edition notes
Trans. None. Written in English by the contributors whose signatures close each article., The Catholic Encyclopedia, An International Work of Reference on the Constitution, Doctrine, Discipline, and History of the Catholic Church, in fifteen volumes, 1907. Public domain.