The name comes from the traditional use of this jewel: small pendant with a tiny box in it where you can keep a lock, a little photography or a miniature.
These lockets had a golden period during the Victorian era, when most of the women used to get it as a gift from their lovers. The purpose was to keep it with them so they can always remember their husbands or couples.
Traditionally they used to wore it pending on a necklace or stuck close to the heart. There are smaller lockets to be hung from bracelets as a tiny decorations.
Some of them had the cover by crystal in order to show the photography inside. Some times the locket allowed until 3 or 4 pictures inside, although it had to be made on that purpose.
During the Victorian era, the decoration of these pieces was very rich. It was usual to find lockets with beautiful flower, birds or other kind of appealing motives. And of course, they were decorated with enamel, precious stones and pearls.
As a curiosity, the first lockets were inspired by the old reliquaries.