Black rings are a fashion trend with roots that reach back to ancient times. Greek artisans carved rings from black onyx, a type of quartz valued for its shine and texture, and Roman craftsmen favored onyx for cameo-style rings that were used as seals. Today, jewelers use modern metals and stones to meet the rising demand for black rings that are worn sometimes just for style but other times to make a statement.

For some, the color black conjures negative images and ideas such as death and emptiness. However, black has also been a color of power, strength and certainty. Black titanium and tungsten wedding bands are a fast-growing trend. Both metals are known for their strength, hardness and endurance. Jewelry manufacturers market the new black wedding bands as traditional symbols of eternal commitment. The new metals and the color black emphasize the strength of that commitment.

According to gemstone historians, Roman warriors carried onyx carvings of gods into battle. The ancients believed black onyx had the power to protect them from both outside threats and internal conflicts and emotions that could cause them harm or lead them astray. Today, black onyx still carries a suggestion of self-control and strength. It is often used for purity rings, a popular symbol of commitment to sexual purity or celibacy.

Black promise rings are an increasingly popular piece of jewelry for both men and women. Historically, promise rings were worn as a symbol of some type of agreement or promise between two people. Today, many people wear promise rings as a sign of friendship or love, and they are often described as pre-engagement rings. Jewelers often laser-etch Celtic endless-knot designs on black titanium and tungsten promise rings. Although art historians agree the knot designs have no symbolic significance, they are often seen as expressions of infinite friendship, loyalty and love.

Diamond rings are the traditional symbol of couples engaged to be married. As one of the hardest and most brilliant gemstones on earth, diamonds are associated with purity, innocence and everlasting love. Black diamond engagement rings are marketed as a sophisticated alternative that reflects the depths of a couple's feelings and the unknown and unlimited possibilities of their lives together.

The popularity of black rings has inspired some groups and organizations to adopt the style to promote an idea or belief. National Marriage Boycott, an organization whose members have vowed to boycott marriage until people of all sexual orientations have the right to marry, has created an equality ring, a black ring emblazoned with the word "equality." A black equality ring is a symbol of the wearer's promise not to marry until gay, lesbian, bisexual and transgender people also have that right.