This International Standard specifies the technical definitions of functional and non-functional horological jewels. It describes the different types of jewels used, and how this is to be marked on a time-keeping instrument or used in advertising.
ISO 1112:1999 history
2009ISO 1112:2009 Horology - Functional and non-functional jewels
1999ISO 1112:1999 Horology - Functional and non-functional jewels
1974ISO 1112:1974 Horology; Functional and non-functional jewels