Here is the official regulation regarding jewelry:
JEWELLERY
6. The only jewellery that may be worn in
uniform shall be a wrist watch, a service-issued ID
tag, a Medical Alert chain identifier, a maximum of
two rings which are not of a costume jewellery
nature and a tie tack/clasp. Additional rings may
only be worn where they indicate professional
standing, such as an engineer, or are worn with a
wedding band as a single set indicating betrothal or
fidelity, e.g., an engagement or an anniversary ring.
Safety regulations should always prevail, especially
in workshops, warehouses or during operations.
a. In addition, female members in uniform
may wear a single pair of plain gold, silver
stud or pearl earrings in pierced ears. The
single stud earring, worn in the centre of
each earlobe, shall be spherical in shape
and shall not exceed 0.6 cm (1/4 in.) in
diameter. (For wear of white pearl earrings;
see Chapter 6, Annex E.) No other type of
earring shall be worn, except for a gold or
silver stud healing device of similar shape
and size, which may be worn while ears are
healing after piercing. Only a single earring
or healing device, worn in the centre of
each earlobe, may be worn at a time (see
Figure 2-2-3). When wearing civilian
clothes on military installations, only one
pair of unobtrusive earrings may be worn.
From Canadian Forces Dress Instructions, A-AD-265-000/AG-001