Sentence:  The large chalice at right is carved from a single chunk of <WSD>sardonyx</WSD>, a kind of onyx. Its gilded rim and base are decorated with tiny enamels depicting a host of popular saints, including Nicephorus (farthest left on rim), a Ninth Century patriarch and opponent of a religious movement to destroy icons. 
Meaning of the word marked with <WSD> tags:  A gemstone having bands of red sard; a variety of onyx or chalcedony.