Citrine

Citrine, also known as false topaz was a variety of quartz whose color ranged from pale yellow to brown.

Description
This semi-precious stone cleaved nicely and was usually facet-cut in brilliant or marquise styles. A typical stone had a base value of 50 gp.

Powers
Any being wearing or carrying a citrine was protected against magic jar spells and spell effects. Ironically, citrine gems were one of the favored receptacles for the "jar" when casting magic jar.