Singer Pharrell Williams spotted wearing a Jacob & Co

Pharrell Williams has built one of the most genuinely knowledgeable watch collections in the entertainment world, but this sighting stands apart. The multi-Grammy-winning producer and singer was photographed wearing what is unmistakably the Jacob & Co Astronomia Tourbillon Ruby Baguette Rainbow — a watch so rare that fewer than two dozen collectors on the planet own one.

The watch is built around Jacob & Co's in-house JCAM09 calibre, a triple-axis tourbillon movement that completes a full rotation of its largest arm every 10 minutes, while the tourbillon cage rotates on its own axis once per minute. The movement operates at 21,600 vph and delivers approximately 60 hours of power reserve. What makes this reference extraordinary, however, is not the movement alone but the total gem transformation of the watch: baguette-cut rubies are invisibly set across the entire 47mm case, bezel, crown, and dial surface — an estimated 450 to 500 individual stones — creating an almost sculptural, monochromatic red object that barely reads as a timepiece at first glance.

The "Rainbow" designation refers to the subtle tonal graduation visible across the ruby paving, where stones shift from deep pigeon-blood red at the periphery to lighter pink-adjacent hues near the dial centre — a setting technique requiring painstaking hand-matching of stones by Jacob & Co's Geneva atelier. The white alligator strap provides deliberate chromatic contrast, a house signature on high-jewellery references.

Pharrell's relationship with Jacob & Co is well-documented. He has previously collaborated with the brand on bespoke pieces and has worn several of their high-complication references publicly. His choice of this watch — worn casually over a striped shirt and tweed vest — reflects his consistent approach of treating ultra-luxury timepieces as everyday personal expression rather than red-carpet artefacts.

With production limited to 18 pieces globally and a UK list price of approximately £760,000 (roughly $960,000 USD at contemporaneous exchange rates), the Astronomia Tourbillon Ruby Baguette Rainbow has no meaningful grey market — when examples do surface privately, they trade at or above retail among a closed circle of serious collectors. It is, by any measure, among the ten most expensive watches Jacob & Co has ever commercially released.