The Russian Blue is a breed of cat. It has a lean medium-sized body and a short, plush blue (a blueish-grey that is the dilute expression of the black gene) coat. This coat is unique to the breed as it is a double coat, with the undercoat being a soft and downy and the longer guard hairs an even blue with the silver tips. This "tipping" gives the coat a shimmering appearance. Its eyes are green and ideally should be dark and vivid. These cats are intelligent and playful but tend to be shy around strangers. They do develop a close bond with their human companions.
Unlike many modern cat breeds, the Russian Blue is a naturally occurring breed which is believed to originate in the port af Archangel, Russia, although the only evidence of this is anecdotal. They are found in many countries, and the majority of their modern breeding program has been carried out in the USA.
Although they have been used on a limited basis to create other breeds (such as the Havana Brown) or add type to a breed in creation (the Nebelung), Russian Blues themselves are shorthaired, blue cats.
Russian Blues should not be confused with 'British Blues' (which are not a distinct breed but rather a British Shorthair with a blue coat), nor the Chartreux or Korat which are two other naturally occurring breeds of blue cats.