A counterweight, or counterbalance, is a weight that is used to offset the weight of another item - basically putting the two in balance.
When you are wearing jewelry, a counterweight is used to keep the jewelry situated in the optimal position. For a bracelet, that might mean it will keep the clasp under your wrist. For a necklace, a counterweight might keep the clasp at the back of the neck or a focal pendant in the optimal position.
An interesting fact is that counterbalances were used on necklaces in ancient Egypt to keep large heavy necklaces in place. The Egyptian counterbalances, called menat (or menit), were protective amulets and part of the overall necklace design.
Necklaces Use Counterweights to Keep Clasps in Back
A pendant necklace on a lightweight chain is one of the best examples of a piece of jewelry in need of a counterweight. If you've ever worn a plain pendant on a chain, you've probably noticed that over the course of the day, the clasp often slides forward and ends up next to the pendant. There are two causes: one is your movement that is rotating the chain in the pendant, and the other is that the weight of the pendant is keeping it stationary, while the necklace chain lacks a significant weight to keep it in place.
The solution to the problem is to add a counterweight such as a charm or decoration on the back of the necklace chain near the clasp to offset the weight of the pendant - putting them in balance.
The size and characteristics of the counterweight can vary depending on the design of the jewelry.
For example, on a lightweight pendant, a simple metal logo tag next to the clasp can be enough of a counterweight. For larger pendants, a more significant weight might be needed. There is a product called Balance Bead that was designed specifically for the purpose of adding a counterweight to pendant necklaces.
The site provides good examples of why you might want to either buy a counterweight such as balance bead or simply incorporate one into your jewelry design.
Bracelets Use Counterweights to Keep the Clasp Hidden
Bracelet designs may also benefit from adding a charm near the clasp. In this case, it is more of a weight than a counterweight - since the idea is to keep the clasp heavier than the rest of the bracelet and therefore keep it at the bottom of your wrist.
Adding a beaded dangle or charm near the loop closure on a bracelet performs several other important functions. It can help make the bracelet easier to clasp by giving you a small item to hold while you hook the jump ring into the clasp. This is also true when using a hook and eye clasp or a toggle clasp. Make sure you add the charm or beads to the jump ring side of the closure, not the clasp. When you drape the bracelet over your hand to clasp it, the additional weight will keep the loop dangling until you can hook it with the clasp.
Make the Weight or Counterweight Decorative
When adding a counterweight to a necklace or a weight to a bracelet, the best part is that you can make it decorative as well as functional. For a bracelet, using a button and loop closure can make a pretty clasp and also provides the necessary weight to keep the closure at the bottom.
Dangles, tassels or charms work equally well to keep the clasp hidden behind the neck on necklaces and under the wrist on bracelets.
And last, remember the concept of adding a weight or a counterweight doesn't only apply to hiding the clasp or closure on jewelry. The idea can also be used in any jewelry design to keep the focal of a bracelet or necklace situated like you intend - particularly with asymmetrical designs.
Make Your Clasp Part of the Jewelry Design
One other option is to make the clasp part of the jewelry design so you don't want to hide it. For necklaces, that could mean hanging a decorative pendant from the clasp and making it part of the design, hanging front and center. For bracelets, it could mean making an oversized decorative clasp that is also the bracelet focal point.