Apoc.

This is the tenth stone of the rational, representing the tribe of Zabulon; it stands fourth in the enumeration of Ezech., xxviii, 13, and is given as the seventh foundation stone of the celestial city in Apoc., xxi, 20.

The Catholic Encyclopedia, Volume 14: Simony-Tournon 1840-1916 1913

CHALCEDONY, Apoc., xxi, 19, chalkedon; Vulg. chalcedonius, the third foundation stone of the celestial Jerusalem.

The Catholic Encyclopedia, Volume 14: Simony-Tournon 1840-1916 1913

Heb., but the twelfth in the Greek; it is called sardonyx and comes in the fifth place in Apoc., xxi, 20.

The Catholic Encyclopedia, Volume 14: Simony-Tournon 1840-1916 1913

This identification, admitted by tradition, rests on the remark that the twelve foundation stones of the celestial city in Apoc., xxi, 19-20, correspond to the twelve stones of the rational, from which it would appear that the ligurus is the same as the hyacinth.

The Catholic Encyclopedia, Volume 14: Simony-Tournon 1840-1916 1913