Laws of Carrying: Clothing & Jewelry
2. Our Sages also prohibited wearing certain types of jewelry in the
public domain. Some jewelry was prohibited to men, and others to
women. [Many of the latter] were prohibited lest a woman remove them
[while in the public domain] in order to show them to a friend. Nowadays,
the prevailing custom is to permit [wearing jewelry on Shabbos in the
public domain], and the halachic authorities have presented a number of
possible justifications for this leniency (1). A G-d-fearing person,
however, should be stringent.
In particular, a man should not go out wearing a ring that does not have an
open seal (2). Similarly, he should not carry a watch, even if it is
hanging on a golden chain around his neck, and is definitely considered a
piece of jewelry. [This prohibition is Rabbinic in origin, however,] a
watch carried in one's pocket is [certainly considered] a "burden" (that
is, an object being transported, as opposed to an article of clothing or
jewelry), and there is absolutely no room for leniency regarding it (3).
(1) See Shulchan Aruch 303:18, and Mishna Berura there. One of the reasons
presented is that nowadays jewelry is more common than it was during the
times the prohibition was created, and it is worn even on weekdays -
something that wasn't true back then. Therefore, we are no longer concerned
that someone might remove a piece of jewelry in the public domain to show
it to a friend, and end up carrying it.
(2) According to the Mishna Berura 303:65, a "Ba'al Nefesh" should not walk
into the public domain wearing any ring at all.
(3) For a discussion as to whether wrist watches may be worn in the public
domain, see Igros Moshe 111, and Chelkas Yaakov Vol.1:89