Sentence:  [B]ooks are your's, / Within whose silent chambers treasure lies / Preserved from age to age; more precious far / Than that accumulated store of gold / And <WSD>orient</WSD> gems, which for a day of need / The Sultan hides within ancestral tombs. 
Meaning of the word marked with <WSD> tags:  Of a pearl or other gem: of great brilliance and value;  bright, lustrous.