"it was gold-plated, and decorated with tiny jade leaves."
chinese jade
Creative Commons Attribution Share Alikechinese jade - Credit: Hadal

Jade is a metamorphic rock, and is considered a symbol of wealth in China.  The appreciation of jade dates back to the neolithic era, when it was used in special ceremonies in ancient China.

It is also highly valued in other Asian nations, including the Koreas, Japan, and India.