broker – n. a person or company that helps other people to reach agreements, to make deals or to buy and sell property

gem-quality – adj. able to be used for jewelry

carat – n. a unit for measuring the weight of jewels (such as diamonds) that is equal to 200 milligrams

sheer – n. when used before a noun: used to emphasize the large amount, size or degree of something

comprehend – n. somewhat formal to understand (something, such as a difficult or complex subject)

rough – adj. having a surface that is not even; in an unfinished or rough state

polished – adj. made smooth and shiny by polishing

crown jewels – n. the crown, scepter and other jeweled objects that a king or queen uses on formal occasions