aristocratic

adjective
1.
of or relating to government by an aristocracy.
2.
belonging to or favoring the aristocracy.
3.
characteristic of an aristocrat; having the manners, values, or qualities associated with the aristocracy:
aristocratic bearing; aristocratic snobbishness.
4.
elegant or stylish in appearance and behavior

While agate could likely be acquired much more cheaply, aristocratic Romans were serious about their agate.