Franck Muller has expanded the use of this material beyond the crystal and now offers options for a clearly superb option in the Vanguard series. 

Carving and shaping solid sapphire blocks into the various elements of a watch case is no mean feat. Each step in the process presents unique challenges and calls for specialized techniques. When mastered, the end results were astonishing and worth the effort to create a three-dimensional window into the watch. Everything about shaping sapphire into watchmaking components is more difficult, more expensive, and more time-consuming. The manufacturing process begins by carving the components from a solid block of optical quality synthetic sapphire. Here, high-speed multi-axis CNC machines are equipped with diamond coated tooling to tackle the challenging material. Imagine this 1^st step as a modern analog to a sculptor taking chisel & mallet to a block of marble and removing most of the excess material to form an outline of the finished work. The next step for processing sapphire will be to use different drills and tools to bring the dimensional tolerance down to a miniscule 0.01mm. Following this, another CNC machine will add finite elements where undercuts, holes, and other precision features are added.

Once the final shape is achieved comes the polishing. A single sapphire case will take days of hand polishing with specialized compounds to achieve the gin-clear quality that will allow light to pass through, and an unhindered view of the inner workings. 

Assembly is the final step. From securing the movement, to holding the front crystal and case back together, the usual practices and methods used on steel, gold or titanium do not apply and unique solutions are called for. Suffice it to say, sapphire is a tough material, and even tougher to work with.

The results of these painstaking techniques are clear (pun intended). As presented in the Vanguard platform, vibrant anodized elements and hand-painted dials stand out in stark relief as colorful works of art - now evident and lit from all sides suspended within a crystalline frame. Collectors will also appreciate that due to the extraordinary scratch resistance of the corundum case, your Vanguard sapphire is sure to remain unmarred and like new every time you put it on your wrist.