Introducing the new RM 07-02 Sapphire Collection by Richard Mille

Explore the new RM 07-02 Sapphire Collection by Richard Mille: advanced engineering meets sapphire cases. Learn how these complex cases are produced.

Richard Mille presented four new RM 07-02 Automatic Sapphire models for ladies, which can be admired from almost every angle thanks to their precious coloured sapphire cases.

Following the first RM 07-02 iteration launched in 2015, these new interpretations are available in lilac sapphire, gem-set pink sapphire, green sapphire, and gem-set green sapphire.

At the heart of 46.75 x 32.90 x 14.35 mm sapphire case is an eye-catching dial distinguished by symmetrical geometric shapes and refined aesthetics. This design showcases the exceptional skills of the master gem-setters.

The stones adorning this watch catch the light to enhance every facet of the sapphire case, decorating the dial, bezel and flange. 

A cabochon also embellishes the crown. Here, precious stones, including diamonds, blue sapphires and yellow sapphires, are combined with ornamental stones such as orange spessartite, white agate or opal, and various shades of green tsavorite, chrysoprase and malachite.

The CRMA5 in-house skeletonised automatic movement, displaying the hours and minutes, is wound by a variable-geometry rotor making it possible to configure the winding of the movement to the activity of the wearer by adjusting two small weights. 

Operating at a frequency of 4 Hz (28,800 vibrations per hour), this compact calibre has a power reserve of approximately 50 hours. The baseplate and bridges – crafted from either red or white gold depending on the version – are microblasted and chamfered by hand. The red gold oscillating weight is set with diamonds for an even more precious result. 

The brand’s iconic tonneau-shaped case is especially difficult to craft in sapphire because of its curved lines (watch the video at the end of this article).

Sapphire will not tolerate even the slightest approximation, particularly during cutting. Its chemical composition gives it an exceptional score of 9 on the Mohs scale of mineral hardness, just behind diamond, which tops the list. 

Creating a case of this quality requires over 1,000 hours of machining, of which 430 hours devoted to preforming the case parts and 350 hours reserved for polishing the entire case. 

The front and rear bezels also receive an anti-reflective coating to guarantee optimal visual properties.

Producing coloured sapphires involves a process that is even more complex than for transparent sapphire: these stones are created by carefully incorporating metal oxides into the material’s crystalline lattice. 

However, a coloured crystal is more sensitive to the heating and growth process than its colourless counterpart. Developing a new shade like lilac therefore involves a multitude of trials before the exact shade can be approved.

The RM 07-02 Automatic Sapphire is limited to seven timepieces for each of the four versions.

With their intricately crafted sapphire cases, gem-set details, and a skeletonised state-of-the-art movement, these timepieces stand out for their remarkable fusion of technical mastery and artistic elegance. richardmille.com

Suggested reading:

- Our visit to the Richard Mille factories

- The history of Richard Mille