Rolex Datejust 31 Yellow Rolesor — Dark Mother-of-Pearl Diamond Dial | Ref. 278343

The Datejust 31 in Yellow Rolesor — Rolex's proprietary combination of Oystersteel and 18 ct yellow gold — represents one of the most accomplished expressions of the mid-size dress watch genre. Reference 278343 pairs the luminous warmth of yellow gold with the corrosion-proof resilience of Oystersteel, a pairing that has defined Rolesor aesthetics since the 1930s. The domed diamond bezel, set with a continuous circuit of brilliant-cut diamonds, frames the dial with geometric precision, each stone individually selected for cut, colour, and carat consistency.

The dark mother-of-pearl dial is a study in natural luminescence. Harvested from bivalve molluscs and carefully sliced to reveal its characteristic iridescent play of light, no two mother-of-pearl dials are entirely alike — each possesses a unique chromatic signature that shifts with ambient lighting. Hour markers set with diamonds further elevate the visual register, catching light from every angle. The calibre 2236, developed specifically for the 31 mm Datejust, is the first Rolex movement to incorporate the Syloxi hairspring — a silicon component machined via deep-reactive ion etching that confers superior isochronism and magnetic resistance compared to traditional metal springs.

With a certified power reserve of 55 hours, the 2236 oscillates at 28,800 vibrations per hour and carries the Superlative Chronometer designation, attesting to accuracy of +/- 2 seconds per day as independently verified by Rolex after casing. The Oyster case provides waterproofness to 100 metres courtesy of the screw-down Triplock crown, while the Jubilee bracelet — five-piece links crafted in Oystersteel and yellow gold — ensures comfortable wear commensurate with the dial's refined character.