A needle without a head, just a point, if used not as a tacshit [jewelry], is permitted to be worn outside. For example, if the needle is used to hold a tichel in place, the lady will not come to carry it as it is needed for tznius.

Chapter 303 Section 10

A lady cannot wear a ring.

Chapter 303 Section 11

A lady cannot wear a pouch of spices so that she will smell nice.