The Formex Essence ThirtyNine Automatic Chronometer Black Pearl Late-August.

At first glance, the Black Pearl reveals little — quiet, understated, elegant. But as light shifts, subtle flashes of rose, soft green, and silvery blue emerge from beneath the dark surface, because the dial is cut from natural mother-of-pearl with a black lacquer applied to its back, letting light pass through the shell's translucent aragonite layers before reflecting back. No two dials behave quite the same, since no two pieces of natural mother-of-pearl are alike.

The 39mm case is 316L stainless steel, just 10mm thick with a 45mm lug-to-lug and 20mm lug width, finished with a vertical brush on the case and bezel and rounded off with hand-finished mirror-polished bevels — a finish echoed across the bracelet links and deployant buckle. The mother-of-pearl dial has the Essence collection's signature horizontal lines machined directly into the shell, paired with gold-plated, hand-applied indices and hands filled with BGW9 Super-LumiNova for low-light legibility. Sapphire crystal front and back (with anti-reflective coating) gives a view of the movement, a screw-down crown brings water resistance to 100m, and the case rides on Formex's patented Case Suspension System.

Power comes from the Swiss-made Sellita SW200-2 Power+, selected in chronometer grade and individually COSC-certified after a rigorous 15-day testing protocol. It runs on 26 jewels and a Glucydur balance wheel, prized for its hardness and resistance to magnetism and deformation, and is fitted with Formex's in-house skeletonized rotor finished with blued screws. On the wrist, the strap or bracelet closes with a carbon-fiber deployant clasp featuring a patented micro-adjustment system, letting the fit expand by 3 or 6mm instantly without opening the clasp or removing the watch.