Gemination is a process in which two things arise out of one. This term is used most frequently to describe the appearance of geminate teeth and geminate consonants. It can also be used in chemistry, usually to describe geminate recombination, in which two chemicals, known as transient species, are produced out of the same reaction. Though this term is not usually used for other purposes, things like identical twins, may be said to arise from gemination as well.
One of the most common examples of gemination produces teeth that do not form correctly. In humans, new teeth develop twice in a person’s life, once in utero and a second time when a child is about five years old. Problems with tooth development can occur in either set of human teeth and arise when the teeth are still forming beneath the gums.
In dentistry, gemination describes the splitting of a single tooth into two teeth. These two teeth may completely separate, breaking through the gums as two distinct teeth, or they may be joined in the middle. These teeth do not usually pose a health risk, though they can be difficult for the next set of teeth to push out, if the geminate teeth are baby teeth. In some cases, a dentist or orthodontist will need to pull these teeth rather than waiting for the adult teeth to push them out.
In the study of linguistics, geminate consonants are consonants that are held for twice the length of time that a normal consonant would be held. Though they are not a feature of all languages, they are an important part of Russian, Arabic, Lugandan, and Latin, among a number of other related languages. Geminate consonants can appear as a feature of intonation or as a way to stress of certain syllables. Constants of double length may also occur as a way to differentiate between two words that are made up of the same series of sounds.
Chemical compounds undergo a process known as geminate recombination. In this process, two chemicals are formed from the same reaction in a single solution. These chemicals react with one another, either immediately or after they have separated out from the parent solution and diffused through it. Depending on the chemicals involved, either or both of these processes may occur, resulting in the same final product which usually consists of a number of new compounds.