Mystery watches, timepieces where the time indications seem to be floating over the dial, are part of the grand history of watchmaking, going back more than 100 years. It should come as no surprise high watchmaking and diamond jewelry house Jacob & Co. has brought the mystery concept back with a contemporary, unique signature twist.

The Mystery Tourbillon Black Spinel by Jacob & Co features a unique accomplishment in watchmaking, the only timepiece with two linked, central, back-to-back triple axis tourbillons. These Siamese twins of high accuracy are intertwined in a high jewelry accomplishment of the highest magnitude. The 50-mm, 18K black gold case is invisibly set with baguette, hexagonal black spinels and the dial is set with hexagonal, "overlapping" black spinels. The sophisticated and ground-breaking Mystery is unique in a great many ways.

Powering this incredible timepiece are two Jacob & Co.'s iconic triple-axis tourbillons. They're placed back-to-back, forming but one single rotating ensemble. The pair rotates on a first axis making a full revolution in 60 second. It makes a full revolution on both the second and third axes in two minutes. Theirs is a unique positioning, as most tourbillons are either set at the twelve or six o'clock position. This is the first time that Jacob & Co., or any other watchmaker for that matter, has placed two tourbillons in the center of the watch, and they're triple axis ones to boot. The power reserve for this high watchmaking, complex and demanding movement is an astounding 60 hours

The Mystery Tourbillon Black Spinel tells time with two mystery disks, rotating around the twin triple axis tourbillons, all the more mysterious as they are drowned in black spinels. The only way to actually tell they're moving would be to constantly gaze at them, or to spot the motions of the two rubies, which serve as indicators like hands would in any other timepiece. The minute disk is set with 119 black spinels (≈ 9.69 ct.) and one ruby (≈ 0.30 ct.) to point the minute. The hour disk is set with 143 black spinels (≈ 8.16 ct.) and one red ruby (≈ 0.19 ct.) to show the hours. The outer ring is set with 120 black spinels (≈ 7.03 ct.). As opposed to every other The Mystery Tourbillon this far, this full black edition is devoid of colored hour markers.

The case of The Mystery Tourbillon Black Spinel is set with baguette hexagonal black spinels according to the invisible setting technique. The dial is set with hexagonal, "overlapping" black spinels. This extremely rare and demanding skill provides the gemstones with extra relief, extra density, which only enhance their incredible effect on the eye.

The 50mm 18K black gold case is completely paved, and there is no crown. The watch is set and wound via two bows located on the case back. In-between the visible parts of the black gold frame, the caseband and lugs are set with 192 black spinels in a mosaic-like, seamless arrangement totaling 15.94 ct.