| 摘要 |
The watch glass (18) is produced by fitting a blank which has the general shape of the glass, made basically from a powder or a mixture of powders of a ceramic material comprising aluminium oxynitride or yttrium oxide, and transparent in the visible spectrum. It has a light absorption coefficient in the visible spectrum which is not more than 30 per cent, and a hardness of at least 1100 Vickers. The water can have a bracelet of articulated links made from a similar material. |
