Montblanc recently introduced the 1858 Split Second Chronograph with a bronze case, black, multi-scale dial, and a monopusher, split-seconds Minerva movement inside. Priced at just 33,500 Swiss francs, it is a bargain as such things go.

Now Montblanc has taken the covers off the one-of-a-kind, titanium version with a blue agate dial created for charity auction Only Watch 2019. Though it costs a bit more – the estimate is 42,000-48,000 Swiss francs – the watch still feels like a steal.

The dial is made of blue agate, a hard, semiprecious stone, with a graduated colour that darkens towards the edges. Design-wise it’s the same as that found on the bronze model: inspired by a 1930s aviator’s chronograph made by Minerva, it has a double chronograph scale – a telemeter on the outer rim and a snail-shaped tachymeter in the middle. The contrast of white and red against the blue dial is both refreshing and striking.

Notably, the dial forgoes the faux-aged “lume” of the bronze model; the cathedral hands and numerals are instead filled with white Super-LumiNova, letting the retro design speak for itself.

The large dimensions of the case remain unchanged from the standard bronze model – 44mm in diameter and 14.55mm high – but it’s significantly lighter thanks to the lightness of titanium.

The sapphire caseback reveals the gorgeous, hand-wound and hand-finished MB M16.31. It is essentially the MB M16.29 derived from a pocket watch movement, but with the addition of a split-seconds mechanism on top.

The MB M16.31 with an additional column wheel for the split seconds mechanism

It is beautifully decorated with Geneva stripes, perlage and anglage, as well as replete with the signature arrowhead chronograph lever and a large balance wheel with an in-house hairspring. The MB M16.31 beats at a low frequency of 2.5Hz and offers a 50-hour power reserve.

The bronze version with the same, gorgeous movement

The watch has an estimate of 42,000-48,000 Swiss francs. It’ll be sold on November 19, 2019 at Christie’s Geneva, and the rest of the Only Watch catalogue can be seen at onlywatch.com.