The Astronomia is the epitome of 21st century ultra-high-end watchmaking and a globally recognized symbol of Jacob & Co watchmaking expertise. A world-first both in the boldness of its unprecedented concept and its entirely mechanical construction, the Astronomia has gone beyond impressive horological achievements and has been regarded as an outstanding multidisciplinary engineering achievement.

The Astronomia Tourbillon Arlequino connects Astronomia with Jacob & Co's singular gem-setting know-how. It is a cinematic sculpture animated by its four-arm movement construction that rotates and floats through the gem-set space inside its spectacular case.

Full of unparalleled watchmaking solutions and adorned with exceptional gems and gem-setting techniques, the Astronomia Tourbillon Arlequino perpetuates Jacob & Co's outstanding reputation in the field of haute horlogerie and haute joaillerie.

The four arms of the Astronomia Tourbillon Baguette carry the triple-axis tourbillon timekeeping organ of the watch, the magnesium globe in hand-painted blue for a spectacular representation of Planet Earth, the exclusive Jacob-Cut® 1-carat spherical diamond with 288 facets, and the differential-leveled, skeletonized time display. This four-arm assembly completes a rotation around the center of the watch and over a spectacular backdrop in 10 minutes. Another astounding feature of the Astronomia Tourbillon Baguette is how each pair of opposing arms are perfectly calculated counterweights of one another - a testament to peerless materials engineering and watch movement design. By having equal weights on these opposing arms, its axles are relieved from strain or increased pull, as the movement takes up different orientations in space.

Whereas the tourbillon was originally invented to be a single-axis, rotating cage to carry the regulating organ of a mechanical pocket watch for improved timekeeping performance, the Astronomia Tourbillon brings this 224-year-old invention to breathtaking levels of modern refinement and complexity.

The triple-axis tourbillon of the Astronomia Tourbillon Baguette is at the forefront of ultra-high-end watchmaking: its delicately decorated cage encapsulates the balance wheel, hairspring, escape wheel and a number of other crucially important components. Characterized by this openworked cage, this constellation of superbly finished components rotates on three axes simultaneously. Following its hand-assembly and specialized fine-tuning procedures, the JCAM10 keeps accurate time throughout its 60-hour power reserve.

A full rotation on the 1st axis takes exactly 60 seconds, as a nod towards the traditional single-axis tourbillon. The 2nd axis of rotation requires 2.5 minutes to complete, while the 3rd axis of rotation is made possible by the 10-minute, four-arm rotating platform of the Astronomia Tourbillon Baguette. This makes for a bold new look at how tourbillons can function, when engineered with cutting-edge, ultra-modern technologies and timeless horological heritage in mind.

Serving as a spectacular backdrop for the satellites turning above is the base dial completely invisibly-set with baguette-cut multi-color gemstones. This makes for a unique coming together of gem-cutting and gem-setting prowess and ultra-high-end watchmaking, as can only ever be experienced in a Jacob & Co creation.

The Jacob-Cut diamond starts out as a much larger rough diamond. First, a rough diamond big enough has to be found, and the purity, clarity, and color has to be of the highest quality both inside and out, and there can be no inclusions. If they start to cut the diamond and find an inclusion, the entire piece will be ruined.

Next, the diamond is cut by machine into a round shape, close in size to the final diamond.

Then, the gem cutter shapes the stone by hand, cutting each individual facet (of 288). This has to be done slowly and carefully, as the stone has to be perfectly round and symmetrical. The danger is that the stone will become oblong and not round. To be used in the Astronomia Collection, the Jacob-cut diamond has to be completely round and weigh exactly as much as the other three satellites (time display, triple-axis tourbillon, magnesium globe).

During the process, if the gem cutter puts slightly too much pressure while adding the facets, too much of the diamond will be cut away, and the ball will end up smaller than the desired diameter. The cutting process takes at least two weeks of dedicated, painstaking work.

To make the final one-carat, Jacob-cut diamond with 288 facets, more than half of the initial rough diamond will be cut away.

The complexity of cutting the 288 facets by hand and making sure everything is symmetrical and the diamond is absolutely round, is what makes the Jacob & Co. diamond used in the Astronomia collection so special.

The Jacob-cut diamond rotates on itself in 30 seconds, while traveling around the dial in 10 minutes.

The globe is made of blue-lacquered magnesium with white gold continents to ensure consistency in weight, as all four satellites have to weigh exactly the same. The globe rotates on itself in 30 seconds, while traveling around the dial in 10 minutes.

The Astronomia Tourbillon Arlequino's case measures 50 millimeters in diameter and 25 millimeters thick between the highest point of its specially curved front sapphire crystal and the lowest point of its case. Crafted from 18K Gold, four sapphire crystal windows installed throughout its periphery to allow for the unhindered viewing of the spectacular caliber inside.

The time display sub-dial of the Astronomia Tourbillon Arlequino is driven through an infinitesimal differential system that allows it to always remain levelled and legible as it rotates together with the movement's four-armed platform across the front of the Astronomia. The Roman numerals on the skeletonized dial are hand-engraved and filled with black lacquer, while the hand-finished hands appear in gun blue metallic.