European Watch Clock and Jewellery Fair 1974 BE 105
“Midnight” - an automatic chronometer by Omega that strikingly combines white gold and a material that is a newcomer to watchmaking : sintered polycrystalline alumina The result is a black-hued “coloured sapphire” which, when yellow gold is used, can be replaced by synthetic ruby. In addition to their beauty, these materiais yield only to diamond in hardness, thereby protecting the watch against damage. (OMEGA “Constellation”)