A finial is an ornament at the apex of a roof or at the top, end, corner of an object. A decorative device. This cufflink is in the shape of a shallow, offset cone. From straight on it has perhaps the appearance of a stylised comet with a centre of mother of pearl from which sculpted 'rays' fan out. There's a nice juxtaposition of bright polished elements against the subtler lustre of mother of pearl, of round against angle, circle with oval and so on. Quite a pretty thing in the rich vein of art deco.