“if it has a signet, it is a man's ornament; if it has no signet, it is a woman's ornament” (Shabbat 60a)
There is a practical side here. Signet rings were items of official identity used for business purposes. Official documents would be sealed with wax and impressed by an identifying signet. So it would be normal for a man to wear one, and unusual in those days for a woman to.
The Gemara commentary does grant an interesting exception to a woman who is a “charity overseer” – evidently someone who needs an official signet to approve charitable disbursements. Interesting to see that this was a position where it was not unusual for find a woman in charge.
More commonly, though, is the clear division between women and men in these texts. For example on our page:
Thus we see that ‘Ulla holds that whatever is fit for a man is not fit for a woman, and whatever is fit for a woman is not fit for a man.
In fact, Ulla seems to hold woman as “a separate people.”
Interestingly, though, there seems to be room for women to do something which had long been considered (even today) only the purvey of men – wearing tefillin.
R. Meir holds that night is a time for tefillin, and the Sabbath [too] is a time for tefillin: thus it is a positive precept not limited by time, and all such are incumbent upon women.
Yes, Rabbi Meir’s view did not hold – either on the times when tefillin worn or on women’s wearing them. But it is interesting that this opening is given.
Strict divisions – and sometimes not so strict.