Metals, like every other solid we encounter, are not what they seem. Some may be a pure element, some may be a mixture, but all are composed of atoms. Atoms are mostly thin air (i.e. nothingness), but contain small charged particles of energy. This isn't a chemistry lesson, but it's important to understand that everything is composed of energy. Metals are a good example of not judging a book by its cover, because many of them can be magnetized. This means that the metal is affected by magnetic force, and has both north and south poles (they're called north and south because that's how a magnet will naturally orient itself). We've all played with magnets as kids, and we know that "opposites attract" when it comes to magnets (+ attracts - and vice versa; + repels + and - repels -). Magnetic force is basically the result of the motion of electric charges (i.e. the charged energy particles that make up atoms, which make up everything else!). All magnets have a magnetic field, a space in which energy is affected by the magnetic force of the magnet. These fields are invisible areas with invisible boundaries that exert very measurable force. What's the big deal about magnets, you ask? Well, the Earth is a magnet. By that I mean that it has a magnetic field, and north and south poles that it orients to (although they're not in the same place as what we call the North Pole and South Pole). The Earth's magnetic field isn't constant - it changes position and strength, and sometimes the poles actually flip. The significance of all of this is that the Earth has its own field of charged energy which responds and manipulates energy particles. This is part of the reason magick works - the Earth influences charged particles of energy, and that's what magick does, too! We are surrounded by a magnetic field that responds to changes in energy. The Earth is a magnet, and when we perform magick, we're a type of magnet as well. We attract energy that we focus and release to cause change. The energy that we release causes ripples in the field of energy that surrounds us, eventually leading to a specific change (i.e. pregnancy from a fertility spell, protection from a shielding spell, etc.).
Below are a few sites that have metal correspondence lists: