The technical highlight of the Arnold and Son Double Tourbillon White Gold Charoite Edition is its complex arrangement of two independent tourbillons, each of which regulates its own time display. Created as a reference to marine travel in the 18th century when a ship’s captain relied on his marine chronometer and astrology for safe passage, each time display can be set accurately and independently to within a minute, giving added usability in time zones offset by 15, 30 or 45 minutes.

Both time zones are displayed on beautifully executed white opal dials each rimmed in gold. The local time is displayed via roman numerals at the 12 o’clock, with the reference time via arabic numerals at the 6, and the effect of the blued, openworked hands against the purity of the opal is superb. The dial plate is of a sliver of exquisite Charoite stone with its mauve tone and delicate bands of white adding further depth, beauty and rarity. Perfectly placed to promote equipoise, generous apertures have been cut into the stone to display the twin tourbillons with the outline giving the arrangement a clover-like shape form.  

At the heart of this impressive display is the manual-winding double tourbillon A&S8513 calibre, which has been meticulously finished with sunray Côtes de Genève, circular graining, snailed decoration on the barrels and hand-polished and chamfering and gold tourbillon bridges. Ensuring further reliability, the two separate gear trains and tourbillon escapement of the Double Tourbillon White Gold Malachite are powered by two mainspring barrels giving 90 hours of power reserve when fully wound. 

The watch resides in an 18ct white gold casing sized at 43.5mm across. Beautifully polished, it carries neat curving lugs and a trim bezel, and is fitted with crowns at the 2 and 7 o’clock positions to enable independent adjustment and winding of the two time zones. Presented as a Unique Piece, the Arnold and Son Double Tourbillon White Gold Malachite wears on a hand-stitched leather strap secured with a white gold clasp.