At that time a sort of small gold medal was fashionable upon which it was customary for noblemen and gentlemen to cause to be engraved certain devices and fancies of their own, and they commonly wore them upon their caps. I made several things of this sort, but found such works very difficult : the celebrated artist Caradosso would not take less than a hundred crowns for one of them, because they contained numerous figures.

A small jewel hanging by a narrow ribbon, so arranged that the ornament comes in the middle of the forehead. So called from the picture in The Louvre

That platinum does not oxidize is one of the primary reasons that antique platinum rings, brooches and other platinum jewelry is so sought after. That, and its resistance to wear, permit antique platinum jewelry to be brought back to life with a good cleaning and polishing, giving the antique jewelry a brilliant look, likely how it originally looked over 100 years ago.

Cellini’s Memoirs shows the use damascening was put to in Renaissance times.

Gold. This beautiful metal always has been the one most used for jewellery, partly because of its rich appearance, partly because it is very easily worked, and also because it does not tarnish.

… the Renaissance was a cultural movement that began in Florence in the Late Middle Ages, eventually spreading throughout Europe.

… a vitreous glaze fused to its base by heat …

A metallic composition of silver, lead, and sulphur. In appearance it is a black substance, somewhat resembling enamel, but it lacks the glassy surface and has a faintly metallic lustre.

Small objects to which magical properties were attributed ; they were often Carried about the person in order to ward off evil spirits (or in some cases attract them).