A locket is a pendant

Pendant

A pendant is a loose-hanging piece of jewellery, generally attached by a small loop to a necklace, when the ensemble may be known as a "pendant necklace". A pendant earring is an earring with a piece hanging down. In modern French "pendant" is the gerund form of “hanging”...

 that opens to reveal a space used for storing a photograph

Photograph

A photograph is an image created by light falling on a light-sensitive surface, usually photographic film or an electronic imager such as a CCD or a CMOS chip. Most photographs are created using a camera, which uses a lens to focus the scene's visible wavelengths of light into a reproduction of...

 or other small item such as a curl of hair. Lockets are usually given to loved ones on holidays such as Valentine's Day

Valentine's Day

Saint Valentine's Day, commonly shortened to Valentine's Day, is an annual commemoration held on February 14 celebrating love and affection between intimate companions. The day is named after one or more early Christian martyrs named Saint Valentine, and was established by Pope Gelasius I in 496...

 and occasions such as Christenings

Infant baptism

Infant baptism is the practice of baptising infants or young children. In theological discussions, the practice is sometimes referred to as paedobaptism or pedobaptism from the Greek pais meaning "child." The practice is sometimes contrasted with what is called "believer's baptism", or...

, wedding

Wedding

A wedding is the ceremony in which two people are united in marriage or a similar institution. Wedding traditions and customs vary greatly between cultures, ethnic groups, religions, countries, and social classes...

s and, most noticeably during the Victorian Age, funeral

Funeral

A funeral is a ceremony for celebrating, sanctifying, or remembering the life of a person who has died. Funerary customs comprise the complex of beliefs and practices used by a culture to remember the dead, from interment itself, to various monuments, prayers, and rituals undertaken in their honor...

s.

Lockets are generally worn on chains around the neck and often hold a photo of the person who gave the locket, or they could form part of a charm bracelet. They come in many shapes such as ovals, hearts and circles and are usually made of precious metals such as gold and silver befitting their status as decorative jewellery.

Lockets usually hold only one or two photographs, but some specially made lockets can hold up to eight. Some lockets have been fashioned as 'spinner' lockets, where the bail

Bail (jewelry)

A bail is a component of certain types of jewelry, mostly necklaces, that is used to attach a pendant or stone. The bail is normally placed in the center of the necklace where the pendant hangs....

 that attaches to the necklace chain is attached but not fixed to the locket itself which is free to spin. This was a common style in the Victorian Age.

Keepsake lockets can also be made with a glass pane at the front so that what is inside can be seen without opening the locket. Such lockets are generally used for items like locks of hair which could fall out and become lost if the locket were repeatedly opened, whereas photograph lockets are generally enclosed on all sides and the photographs are secured by pieces of clear plastic.

Another kind of locket is/was made in a filigree

Filigree

Filigree is a delicate kind of jewellery metalwork made with twisted threads usually of gold and silver or stitching of the same curving motifs. It often suggests lace, and in recent centuries remains popular in Indian and other Asian metalwork, and French from 1660 to the late 19th century...

 style with a small cushion in the centre to which a few drops of perfume should be added. Perfume lockets were popular in eras when personal hygiene was restricted and sweet smelling perfume was used to mask the odour of a person or their companions.

Very rare World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

- and World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

-era British

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 and American military uniform locket button

Button

In modern clothing and fashion design, a button is a small fastener, most commonly made of plastic, but also frequently of seashell, which secures two pieces of fabric together. In archaeology, a button can be a significant artifact. In the applied arts and in craft, a button can be an example of...

s exist, containing miniature working compass

Compass

A compass is a navigational instrument that shows directions in a frame of reference that is stationary relative to the surface of the earth. The frame of reference defines the four cardinal directions – north, south, east, and west. Intermediate directions are also defined...

es.

The Locket also refers to a book by Richard Paul Evans

Richard Paul Evans

Richard Paul Evans is an American author.-Biography:Evans graduated from Cottonwood High School in Salt Lake City. He graduated with a B.A. degree from the University of Utah in 1984. While working as an advertising executive he wrote a Christmas story for his children...

 and the Season 2 Farscape

Farscape

Farscape is an Australian-American science fiction television series filmed in Australia and produced originally for the Nine Network. The series was conceived by Rockne S. O'Bannon and produced by Jim Henson Productions and Hallmark Entertainment...

episode.