Arnold & Son fans might love the Luna Magna Ultimate II even more, with its blue–green Paraíba tones and PVD-treated ruthenium crystals.

It’s based on Arnold & Son’s three-dimensional moon model, with a 44 mm diameter case made from 18 ct white gold and studded with 7·62 ct diamonds. Surrounding the watch are 112 baguette-cut diamonds with a total of 5·90 ct. The dial itself is made from millions of pure ruthenium crystals. A three-dimensional moon passes under the time display, with the white gold globe pavé-set with 161 brilliant-cut diamonds, and an equal number of Paraíba tourmalines for the parts in shadow.

The Luna Magna Ultimate II features the A&S1021 hand-wound calibre, and will reflect the lunar cycle accurately, taking 122 years for it to fall a day out. (When that happens, it’s easy to correct.) The strap is in alligator skin, with a hand-stitched pin buckle in 18 ct white gold set with 26 baguette-cut diamonds totalling c. 0·97 ct.

Arnold & Son will make a limited edition of eight of these timepieces, each priced at SFr.199,900 including tax.