An article in the maiden issue of Xavier, the school organ, which saw light in March 1963, explains the meaning of the coat-of-arms. The article is reproduced here in its entirety. After presenting a drawing of the new coat-of-arms, which is exactly the present one, the article goes on to say:
As you may have noticed from school stickers and pins, the shape of the emblem is a shield. In heraldic language this particular shape is called “l’écu français” in modern form. The face, or escutcheon, is divided by a vertical line. From the point of view of the observer, the left side is called the Dexter side, and the right side, the Sinister side.
The Dexter side of the escutcheon represents the school and its aim. On an azure background are two suns, one superimposed on the other. The twelve-pointed silver sun represents China; the gold sun, with eight bundles of rays represents the Philippines; and on the center of the sun is the blazon of the Society of Jesus with the monogram, IHS, with the H surmounted by a cross, and beneath the three nails. The design carries a beautiful meaning, that in this school, the Society of Jesus acts as a bond to unite China and the Philippines.
The Sinister side is the authentic blazon of the Javier family, Francis Xavier being the patron of the school. The heraldic formula shows a black- and-silver-checkered crescent reversed above a black and silver checkerboard bank upon a Gules background.
The meaning of this coat-of-arms is gathered from the authoritative interpretation of Rev. Father Reconde, S.J., of Javier’s Castle, Navarre. The Crescent was the motif granted by Sancho VII, King of Navarre, to a member of the Xavier family, Don Ladron, the first Mayor of Javier (Navarre), for his valiant and victorious fight in the battle of Las Navas de Tolosa in 1212, the last great and final victory of Spain against the Saracens. The black and silver squares in the checkerboard band have been interpreted in Navarre’s heraldry as symbols of the courage and military prowess of the Javier family, since the chess board in the Middle Ages was meant to express the preparedness to “gamble one’s life on the chess board,” or as we would say, to lay it down on the line. Finally, the background of Gules which, in heraldry, stands for red, means the bloody and heroic sacrifice paid for every daring and sublime undertaking.
But the emblem is incomplete without a motto. The motto of Xavier School is “Luceat Lux,” “Let the Light Shine,” a ringing echo of the Chinese name of the school Kuang Chi.
The above is an excerpt from Chapter 3 of Fr. Santos Mena, SJ’s book, Luceat Lux: The Story of Xavier School.