Abaculus
Abaculus (ȧb*ak"u*lus) , noun
[Latin, dim. of abacus.]
(Architecture) A small tile of glass, marble, or other substance, of various colors, used in making ornamental patterns in mosaic pavements. — Fairholt
Abaculus (ȧb*ak"u*lus) , noun
[Latin, dim. of abacus.]