Considered to be the king of all gemstones, diamond is the hardest natural material in the world. The quality of diamond is classed according to the “four C's”:Cut: The more facets the stone has, the more intensely it reflects the light. Certina uses brilliants (full-cut diamonds) in its watch-cases and single-cut diamonds on dials.Colour: At first sight you might think that diamonds are white. Experts, however, can identify their subtle shades of colour. Certina uses Top Wesselton diamonds only.Clarity: Almost all diamonds have tiny flaws, called inclusions, which can be seen with a jeweller’s loupe. Certina uses stones in the highly desirable VSI – very small inclusions – class.Carat: The unit indicating the weight of a diamond. One carat is equivalent to 0.2g.Certina only uses diamonds which meet the requirements of the Kimberley Process, an international system for certifying raw diamonds. The system aims to stop the trade in smuggled diamonds (so-called “blood diamonds”).

This organic material, which Certina uses for particularly precious dials on women's watches, comes from the innermost layer of shell of some molluscs. Iridescent, shimmery mother-of-pearl is very brittle and must be processed with great care, which makes it even more valuable.

Sapphire watch crystal is made of aluminium oxide power (Al2O3) heated to over 2000°C. The resultant sapphire nugget is cut with great precision into fine slices, trimmed and polished. Sapphire is extremely scratch-resistant, shock-resistant and is very transparent. This is why sapphire crystal is an essential element in the DS Concept and is used by Certina in all of its models to protect the dials.