There is arguably no better symbol of the Jacob & Co motto, "Inspired by the Impossible," than the Astronomia. Its high horology movement broke boundaries in the Swiss watch industry. The versatile in-house caliber has been used in timepieces with themes ranging from fine art to high stakes gambling.

The newest iteration of this timepiece is the one-of-a-kind Astronomia Skull. The dial of the 50 mm watch contains a crypt of skulls and bones sculpted out of 45 grams of 18k white gold intertwined among the well-known complications of this movement.

These include a Double Axis Tourbillon and the two iconic symbols of the Astronomia: a 1-carat diamond that features the exclusive Jacob Cut with 288 facets and a magnesium Earth globe. This unique piece combines exceptional mechanics with high artisan crafts.

Throughout history, still life depiction of skulls has brought about an ever changing range of emotions. For the Astronomia Skulls, the dial and the domed sapphire crystal reveal a crypt filled with skulls and bones. This sophisticated, three-dimensional layout is the work of highly skilled artisans who hand-sculpted this scene in precise detail. Approximately 200 hours of work over a six-month period went into creating this scene.

The five most prominent three-dimensional skulls are in highly polished 18k white gold contrasted with deep ruby eyes. Smaller skulls peek out from below. More skulls appear on the minute-and-hour subdial serving as markers for 12, 3, 6, and 9 o'clock with crossbones in between. This unique piece serves as a reminder of the transitory nature of human existence and is steeped in a rich artistic tradition that dates back to antiquity.

World class metalsmiths use Old World techniques to take approximately 45 grams of 18k white gold and turn it into the Memento Mori display. The skulls and bones are done in sections crafted and polished by hand using both modern and ancient tools. Gem-place rubies in the eyes of the most prominent skulls. The same care goes into the display's bones so it fits in a way that looks natural and organic. The layers of skulls and bones are placed in perfect harmony with the delicate watch complications.

The tourbillon was originally invented to be a single-axis, rotating cage to carry the regulating organ of a mechanical watch for improved timekeeping performance. The Astronomia Art Skulls presents this 224-year-old invention in a yet more spectacular way. It rotates on two different axes. One is horizontal and spins in 60 seconds. The other is vertical and spins in 5 minutes.

The one-minute flying tourbillon of the Astronomia Art Skulls features a delicately decorated cage that encapsulates the balance wheel, hairspring and escape wheel. This openworked cage is only secured from underneath, which makes it a flying tourbillon. It is a constellation of superbly finished components that, when assembled and fine-tuned expertly, allows calibre JCAM25 to keep accurate time throughout its 48-hour power reserve.

The special 288-facet Jacob-Cut Diamond is a feature of the Astronomia collection. There is only one vendor in the world that can produce this patented cut. 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 Jacob-Cut diamond starts out as a circular 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. There can be no inclusions. If one is found during the cutting, 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 one of the 288 individual facets. This has to be done slowly and carefully, as the stone has to be perfectly round and symmetrical. The risk is that the stone will become oblong and not round. To be used in the Astronomia Collection, the Jacob-cut diamond has to be perfectly round and weigh exactly as much as the other three satellites (time display, tourbillon, magnesium globe). The cutting process takes at least two weeks of dedicated, painstaking work.

The resulting, 1-ct Jacob-cut diamond is constantly spinning on itself in 60 seconds.

The globe represents the Earth. It's 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 60 seconds.

The Astronomia Art Skull's case measures 50 millimeters in diameter and 25 millimeters thick. Crafted from 18K white gold, it's fitted with a special domed sapphire crystal and four sapphire crystal windows installed throughout the periphery, allowing for unhindered viewing of the spectacular caliber and the artwork inside. The lugs of this incredible timepiece are set with 80 baguette-cut diamonds (≈ 6.10 ct.).

The hands on the skeletonized dial are gun-blue metallic, while hand-shaped bones and skulls surround the hands.