Skull Tourbillons

Skull Tourbillons
Richard Mille's RM 52-01 Tourbillon Skull Nano-ceramic ($720,000).

They may seem like a recent punk fashion, but objects decorated with skull and crossbones have been with us for thousands of years as reminders that life is short and should be lived to the fullest. (In Latin memento mori, or "remember that you must die.") Skull-themed watches—perfect devices for marking our numbered days, hours and minutes—have a fascinating history that dates at least to 1504 with a piece credited to German watchmaker Peter Henlein, who specialized in portable, ornamental clocks meant as badges of excessive wealth.

Mary Queen of Scots bestowed another 16th-Century example on her maid of honor, Mary Seaton. Shaped like a skull and elaborately engraved with religious scenes, figures of Death and lines from the poems of Horace, it has a hinged jaw that reveals the dial with a single hour hand, and the movement occupies the space where the brain would be.

A more modern treasure is Richard Mille's $720,000 RM 52-01 Tourbillon Skull Nano-ceramic, a one-of-a-kind descendant of the 2013 model, which was limited to 30 pieces. Distinguished by different gems, each unique skull tourbillon expresses not only Mille's renegade style of watchmaking, but also displays his inspired use of cutting-edge materials rarely seen in watches. The watch's case is made of a groundbreaking composite material called nano-ceramic, while the case back and bezel are TZP, made from 95 percent yttrium-stabilized zirconium, which provides extreme scratch-resistance. A carbon-nanotube inner case protects the manually wound tourbillon movement from shocks.

Exotic materials also endow Hublot's 45mm Classic Fusion Skull Tourbillon Black Skull ($114,900) with robustness and lightness. The case, crown and dial elements are made of micro-blasted ceramic-coated aluminum, which wears as hard as ceramic at half the weight. A 3-D machining process sculpts the bridges of the skeleton tourbillon into bony shapes. An open-worked skull-shaped barret, or bridge, secures the spinning tourbillon at 6 o'clock.

While skull motifs have been in Peter Speake-Marin's repertoire for more than a decade, this year marks the first time the English watchmaker has produced a skull-themed tourbillon. The Skull Face to Face Tourbillon ($155,000) is limited to eight pieces. The 18-karat red-gold dial is etched using a special chemical process to depict two skulls facing each other on each side of the hand-finished 60-second Magister Tourbillon spinning in an aperture at 6 o'clock. The bezel is set with 36 baguette gems in a nod to the notion that, unlike us, "diamonds are forever."

Those whose pockets aren't deep enough for an ultra-complicated skull tourbillon set with precious gems can still get into the memento mori spirit with more approachable watches from Bell & Ross, Pierre DeRoche, Romain Jerome and others. Tempus fugit, so carpe diem!