Rolex Lady-Datejust 31 31 mm 278343RBRBMDO Steel/Yellow Gold/Diamonds Black Mother of Pearl

The Rolex Lady-Datejust is one of the most enduring icons in watchmaking history, and the 31mm case size occupies a sweet spot between the classic 28mm Lady-Datejust and the full-size 36mm Datejust, offering a versatile fit on a wide range of wrists. Introduced as a natural evolution of the original Datejust—itself the world's first self-winding wristwatch to display the date in a magnified window on the dial—the Lady-Datejust has been a symbol of refined achievement and timeless style for decades. Reference 278343RBRBMDO represents the model at its most luxurious, blending sportive durability with high-jewelry drama.

The 31mm Oyster case is built from Rolex's proprietary Oystersteel, a corrosion-resistant alloy in the 904L stainless steel family, enriched with polished 18k yellow gold accents in the classic two-tone "Rolesor" configuration. The Oyster case architecture—featuring a screw-down crown, screw-back case, and monobloc middle case machined from a solid block of metal—provides water resistance to 100 meters (330 feet), making this a watch that can move effortlessly from boardroom to pool. The integration of precious metal and steel gives the 278343RBRBMDO a warm, jewel-like quality without sacrificing the ruggedness Rolex is famous for.

The crown jewel of this reference is literally its bezel: a yellow gold domed setting paved with brilliant-cut diamonds. This diamond bezel catches light from every angle, transforming the watch into a wearable work of art. It frames the black mother-of-pearl dial—a material prized for its organic iridescence, in which subtle violet, green, and blue hues shift with the light against a deep, velvety black ground. The contrast between the sparkling diamond bezel and the dark, luminous dial is visually arresting and deeply feminine, a combination that photograph beautifully and captivates in person.

Powering the 278343RBRBMDO is a Rolex Automatic movement, the hallmark of the brand's commitment to precision and self-sufficiency. Rolex automatic movements are chronometer-certified by the Swiss Official Chronometer Testing Institute (COSC) and then further regulated by Rolex to even tighter tolerances in-house, ensuring accuracy that meets or exceeds official standards day after day. The movement is housed within the hermetically sealed Oyster case, protected from dust, moisture, and shock—delivering reliability that Rolex has refined over generations.

On the wrist, the 31mm Lady-Datejust 278343RBRBMDO sits with quiet authority. The Oyster bracelet—crafted in matching Oystersteel and yellow gold links—lies flat and comfortable, secured by Rolex's discreet folding Oysterclasp. The bracelet's satin-finished center links contrast with polished outer links, a detail that complements the interplay of gold and steel throughout the case. This is a watch designed to be worn every day and treasured for life, suitable as an heirloom, a milestone gift, or a signature piece for the discerning collector.

At Bizak & Co., we offer this certified authentic, brand-new Rolex Lady-Datejust 31 reference 278343RBRBMDO with full confidence in its provenance. As a trusted luxury watch dealer, we are committed to transparency, expertise, and exceptional client service. Whether you are buying your first Rolex or adding a statement piece to an established collection, our team is ready to assist. Contact us or browse our inventory at bizakandco.com to secure this exceptional timepiece today.