News · Jacob & Co.

Jacob & Co. sets the four-axis Astronomia over green stones

The six-piece rose-gold edition turns its tourbillon through four axes above a faceted gemstone base.

Hen & Mills Editorial · 4 min read · 29 August 2026

• A 60-second central platform carries a tourbillon rotating through three further axes in 60, 18 and 15 seconds during every minute.
• The hand-wound JCAM54 has 485 components, a constant-force release every one-sixth of a second and 36 hours of reserve per winding.
• Production is limited to six pieces, each listed in stock at US$770,000; Jacob & Co. publishes no official Australian price.

Jacob & Co. has set a one-minute carousel above a bed of green gemstones. The rose-gold frame, transparent case band and faceted ground turn the movement into a three-dimensional display, with the watch designed to be viewed from the side as well as the front. Six pieces will be made at US$770,000 each, combining the fast four-axis construction with a new setting in the Jacob & Co. Astronomia Four-Axis Tourbillon - Rose Gold (Green).

The 18-carat rose-gold case is 47mm across and 27mm thick, dimensions set by the rotating architecture and the clear volume around it. A single block of sapphire forms the case band and a curved, anti-reflective sapphire crystal covers the top. Rose-gold pillars and lugs hold those transparent sections together, leaving the mechanism visible through most angles. The height therefore encloses a display space, not only a stack of plates beneath a conventional dial.

Four rotations inside one minute

At the centre is a vertical rotating platform that completes one revolution every 60 seconds. The tourbillon mounted on it rotates through three additional axes: one in 60 seconds, one in 18 seconds and one in 15 seconds. Counting the platform gives the watch its four axes. Those short periods keep the cage in near-constant motion and bring every viewing angle around during a brief look through the sapphire case.

The hand-wound JCAM54 contains 485 components, runs at 21,600 vibrations an hour and provides 36 hours of reserve. A constant-force system releases energy every one-sixth of a second, isolating the tourbillon from changes in mainspring torque. Revolution reports that earlier Astronomia platforms could take several minutes to circle the dial; reducing the central rotation to 60 seconds makes the carousel part of the seconds display as well as the architecture, while keeping the tourbillon moving across the available views.

Time is shown on an off-centre dial that remains upright as the platform turns. A differential compensates for the carousel's rotation, so the hour and minute display does not spin with the structure beneath it. The mechanism therefore separates the readable indication from the moving stage even though both travel around the case. Without that correction, the spectacle would make the time unreadable for much of each minute and reduce the dial to another rotating component.

Green stones under the carousel

The base is assembled from faceted green crystals that reflect light through the sapphire case and around the rose-gold movement components, producing a different effect from a flat pavé dial. The stones form the landscape while the time display and tourbillon move above it. That depth explains much of the 27mm height. The watch will remain physically imposing, but the transparent band and open centre prevent the case from reading as one solid block of gold from most angles.

Water resistance is 30 metres, and an alligator strap is secured by an 18-carat rose-gold buckle. Revolution describes a hinged tab on the rear for setting the time, leaving the sapphire case band uninterrupted. That rear control keeps the lateral views clear and avoids placing a large setting piece beside the rotating platform. The practical boundaries are plain: the watch is an exhibition structure built around a kinetic movement and gemstone setting, not a design for water or unobtrusive daily wear.

Jacob & Co. Astronomia Four-Axis Tourbillon - Rose Gold (Green) pricing and availability

Reference AT180.40.AB.AC.A is limited to six pieces. Revolution reported US$700,000 at introduction, while Jacob & Co.'s current structured product data lists the watch in stock at US$770,000; the latter is the current list price used here. Enquiries run through the official product page and boutiques. The brand publishes no Australian-dollar price, so none is converted, and no delivery date is stated beyond the in-stock status. The official page remains the source for current stock status.

The rotations still lead

Other Astronomia Four-Axis variants use red stones, colourless gemstones, mother-of-pearl with blue aventurine, labradorite, hematite and opal. The green model changes the material below the mechanism, affecting the light travelling through the entire case instead of limiting the colour to a strap or conventional dial. It also keeps the central architecture easy to separate visually: rose gold frames the calibre, green supplies the ground and sapphire leaves the moving parts open from the front and sides.

The numbers remain the clearest summary. A 60-second platform carries a tourbillon turning through 60-, 18- and 15-second axes, backed by 485 components and a constant-force release six times each second. The gemstones change the atmosphere and the rose-gold frame changes its warmth, but that compact sequence of rotations remains the reason the Astronomia needs so much transparent space. The setting supports the movement's theatre through colour without replacing its mechanical premise.