A fine example of a marble ‘opus sectile’ mosaic pavement. Byzantine, 11th century.

Opus sectile is an art technique popularized in the ancient Roman and medieval world where materials were cut and inlaid into walls and floors to make a picture or pattern. Common materials were marble, mother-of-pearl, and glass. The materials were cut in thin pieces, polished, then trimmed further according to a chosen pattern. Unlike tessellated mosaic techniques, where the placement of very small uniformly sized pieces forms a picture, opus sectile pieces are much larger and can be shaped to define large parts of the design.

Correspondent: J.M.Criel, Antwerpen.
Source: Website of ‘stnicholascenter.org’ & Wikipedia.

Another viewer suggested in addition: 8 symbolized the eternity and therefore was taken by the Christians to express the eternal life. This same graphic symbol was taken after by the muslims and is known as Rub El Hizb (en arabe : rubʿ al-ḥizb, ربع الحزب, « quart de section » (see wikipedia) to mark the end of one of the 2 x 4 divisions of the part of the monthly recitation of the Coran - that is the eigth of that monthly part.

A 8-dented star (but without the circle inside) is in India the symbol of Ashta Lakshmi (Sanskrit: अष्टलक्ष्मी,Aṣṭalakṣmī, lit. "eight Lakshmis") which is the group of the eight secondary manifestations of goddess Lakshmi, who preside over eight sources of wealth and thus represent the powers of Shri-Lakshmi that is a goddess of beauty, wealth, prosperity or auspiciousness.(see wikipedia)

Finally, a probably very antique oriental symbol re-utilized by the hindouists (Vedas) as well as by the medieval christians and the muslims.