Single-crystal sapphire.
A4. Five millimetres.
Colourless grown corundum, nine on the Mohs scale, second only to diamond, the same material trusted in observatory windows. It does not scratch in ordinary use, does not fade or yellow, and withstands fire and water far beyond anything on paper. It is chosen to outlast the languages it is written in.
The optical-grade sapphire is grown in China, then cut and polished in Switzerland by our specialist sapphire workshop.
The front carries the family's chosen words. The back carries the lighthouse mark and the edition number: Nº I, then Nº II, and so on. The front belongs to the family. The back belongs to the record.
