Oxidized sterling chai disc pendant on 16" sterling silver chain.
The word Chai is made up of two letters of the Hebrew alphabet - Chet ( ח) and Yod ( י), forming the word "chai", meaning "alive", or "living". In Hebrew, the related word chaya ( חיה) means "living thing" or "animal", and is derived from the Hebrew word chai ( חי), meaning "life"
Many believe that the letters of chai add up to 18. For this reason, 18 is a spiritual number in Judaism, and many give gifts of money in multiples of 18 as a result.