Keystones The central or topmost stone of an arch. This in some styles is made different in size from the other voussoirs, or projects, or is decorated with carving.

Lysicrates Small decorative structures erected in ancient Greece to commemorate the victory of the leader of a chorus in the competitive choral dances. The best known is that of Lysicrates (c.335 B.C.), still standing in Athens , a graceful circular structure showing one of the early uses of Corinthian columns.

Marquetry Material, such as wood or ivory, laid piece by piece into a wood surface in a detailed design and veneered to another surface, especially of furniture, for decoration.

Monolithic Constituting a monolith: a monolithic sculpture; Massive, solid, and uniform: the monolithic proportions of Stalinist architecture; Constituting or acting as a single, often rigid, uniform whole: a monolithic worldwide movement.

Motif A dominant recurrent thematic element in an artistic or literary work..

Mosaic A picture or decorative design, or the process of making the design, made by setting small colored pieces, as of stone or tile, into a surface.

Numidia An ancient country of northwest Africa corresponding roughly to present-day Algeria . It was part of the Carthaginian empire before the Punic Wars and became a separate kingdom after 201 B.C. Conquered by Rome in 46 B.C. and invaded by the Vandals in the fifth century A.D., Numidia was overrun by the Arabs in the eighth century.

Onyx A chalcedony that occurs in bands of different colors and is used as a gemstone, especially in cameos and intaglios.

Palmettes A stylized palm leaf used as a decorative element, notably in Persian rugs and in classical moldings, reliefs, frescoes, and vase paintings.

Pediments In classical architecture a pediment was the triangular space forming the gable of a simple roof. It later came to mean a similar form used as a decoration over porticoes, doors, windows, etc.; and also, a rounded or broken frontal having a similar position and use.

Pilasters In architecture a pilaster is an upright architectural member right-angled in plan, constructionally a pier but architecturally corresponding to a column, having capital, shaft, and base to agree with those of the columns of the same order. In most cases the projection from the wall is one third of its width, or less.