A ring is an item of jewelry worn on the finger. It can be made from almost any hard material and may be set with stones or other items. Rings are usually worn on the finger, although they can also be worn on other parts of the body, such as the neck, arm, and toe. Rings can be made from gold, silver, tungsten carbide, titanium, palladium, and even plastic. They can be decorated with engravings or inlaid with gemstones. They can be engraved with names, dates, and other symbols, or have cut edges that can be polished to be a little more rounded. Rings are often given as a symbol of love, marriage, or engagement and are sometimes associated with specific religious practices.
The study of rings first emerged as a mathematical structure generalizing fields. Rings are algebraic structures equipped with two binary operations satisfying properties similar to those of addition and multiplication. A ring is closed and associative, and its elements are commutative under multiplication: (a + b) ab for all a, b in the ring. Informally, a ring is an integral domain if it has no divisors of zero and a unit element is the identity ring. This type of ring is used extensively in number theory, invariant theory, and algebraic geometry.
When describing a ring to another person, it is important to accurately describe its size. This can be done using the international standard based on the diameter of the ring’s band, or by indicating the ring’s circumference in inches or millimeters. It is also helpful to note any special features of the ring, such as its setting. A prong setting has thin metal “claws” that extend from the ring to hold a center stone, and cluster settings have small gems sharing the same space with one large stone.
It is also important to specify any inclusions in the ring’s stone(s), as these can affect its value and durability. Some accidental inclusions decrease the stone’s value while carefully crafted inclusions can enhance it.
Rings have been worn for thousands of years, and the number of different styles is enormous. In ancient Egypt, there were signet rings, in which a seal was engraved to authenticate documents; memorial rings, upon which was carved the name or effigy of a deceased loved one; posy rings, which had a short inscription or line of poetry; and vow rings that signified a promise or commitment. In Rome, rings were a mark of social status.
Some people wear rings for spiritual or cultural reasons, while others do so purely out of personal preference or vanity. In some cultures, wearing particular types of rings is believed to bring good luck or protection from evil. For example, rings with talisman stones are commonly sold in mystical stores and can be bought for the purpose of protection or good fortune. In other areas of the world, rings are worn as a symbol of religious faith or to commemorate special occasions such as a wedding or anniversary.