The following is a guide to the difference between a lobster claw clasp, hook and eye clasp and box clasp. These are three of the various types of clasps used to close a necklace or bracelet.
Lobster Claw Clasp - the name of this clasp is very descriptive as to its appearance and how it works. This clasp operates on a spring - you push back on a lever to open the claw - release the lever and it snaps shut. Lobster claw clasps are usually oblong but can also be round.
When purchasing a piece of jewelry with a lobster claw clasp make sure the clasp both closes completely and is fairly easy to open. You do not want to rip the skin under your fingernail every time you want to wear this piece of jewelry.
Also, lobster claw clasps are not the most user friendly for jewelry wearer that have arthritis or other issues causing limited use of their hands or fingers.
Hook and Eye Clasps - a very simple closure system that works by inserting the hook on one side into the 'eye' or circle on the other. Very easy to use but not the most secure way to fasten a necklace or bracelet.
Usually the weight of a necklace cause the necklace to hang down, using gravity to keep the clasp secure but keep on eye on your jewelry if you move around a lot. Smaller hook and eye assemblies are more appropriate for bracelets.
Box clasp - this type of clasp has a 'V' shaped tab on one side that is inserted into a box on the other. The tab clicks into the box - when you want to remove the piece of jewelry the back part of the tab is compressed between two fingers so the tab can be pulled from the box. Unlike what is implied by the name - the shape of box clasps are not always square or rectangular like a box.
Box clasp assemblies that are small are used for lighter weight necklaces such as pearls or small gemstones. Some jewelry designers use large, decorative box clasp assemblies that are set with gemstones or etched with decorative symbols. While simple clasps are usually worn in the back of the neck or the underside of the wrist, this type of box clasp is meant to be worn in front, in a pendant like fashion.
The next article in this series on how jewelry works will discuss magnetic clasps, toggle clasps and slide lock clasps.