Body Jewelry is classified by shape.

Curved Barbells come in all kinds of decorative designs, with gems, with dangles. The Gem Bottom is always non-removable. Only the top ball is threaded.

Whenever there is a jewel or decoration,
it is usually fixed and cannot be removed.
 
Always try to remove the plain ball first.

If both sides are decorated or have gems,
the smaller gem ball is the threaded one.