The Roman matrons of the I-II sec.d.C. they used to dress up with large pins in your hair both to allow them to sustain elaborate hairstyles, that for pure vanity.
These pins were indeed real jewelry, therefore suitable to serve a decorative function as well as utility.
They were made of precious materials like gold and silver, or, most commonly, of ivory; They were constituted by a pointed end, to be inserted between the crowns, and another worked, generally, shaped head, as small sculptures.
It does not end here.
In a violent society like the Roman one you could never rest easy and pins, if necessary, could become defense weapons moderately effective.
It is said that Fulvia, wife of Marco Antonio, it is wildly fierce on the lifeless body of Cicero trafiggendogli with one of these pins language, guilty of having been excessively stinging towards her husband. (Photo gives: unarosadoro.com)