Amulet of perpetual youth

A brooch of perpetual youth was a talisman that when worn made the wearer appear young and have a youthful appearance, similar to a Phylactery of long years In human years one wearing the brooch might appear 28 years old. In other races the apparent age would be different. One well known wearer of such a brooch was Gromph Baenre, Archmage of Menzoberranzan. The brooch was obviously magical, yet had mysterious properties. One such property was that the magic of the brooch could in no way be canceled or dispelled. Gromph had frequently erected anti-magic shells around himself yet continued to remain young via the magic of the brooch. Also, the brooch had no effect on a child of any race if worn. The magic somehow attuned itself to whatever race wore it, and the magic would not take effect unless it sensed that the wearer was above a certain age. Obviously, much more study was required to understand the full characteristics of the brooch of perpetual youth.