Is Onyx magnetic?

Most types of Iron are magnetic, however depending on its composition and purity, there are kinds that are not magnetic. For example, Steel is mostly Iron, Carbon, and a few other lesser materials,...

The element nickel is attracted to a magnet. Many "nickel" items contain large amounts of other metals so they're not strongly attracted however. For example, US 5¢ coins are called nickels but...

They have the electromagnetic force in which two objects are attracted to one another in a specific field or range.

Non magnetic

Francium is supposed to be paramagnetic.