Posted on

Jacob & Co. Brilliant Skeleton Jewelry

From the show-stopping brilliance of the 409 white diamonds that adorn its 18k rose or white gold case, crown, bezel and buckle, to the captivating intricacy of its open-work skeleton movement, the Jacob & Co. Brilliant Skeleton Jewelry timepiece is a fusion of time and light – a masterpiece that combines the classic art of the skeleton watch with the jeweler’s art of meticulous, invisible gem setting. This is a dazzling marriage of high-level mechanics with high-octane glamour.

The Jacob & Co. Brilliant Skeleton Jewelry shines the limelight on every lovingly crafted component of the movement through its sapphire crystal front and case back. As is the tradition with skeleton watches, all non-essential metal on mechanical parts of the watch has been trimmed away, including on the bridge, plate and wheel train, leaving just the barest skeleton of the spectacularly executed movement that makes the watch tick, with the hand-wound balance wheel seemingly suspended at 6 o’ clock.
Thanks to the dedicated, detailed work by gifted gem setters in the Jacob & Co. Geneva atelier, who have over half a century of experience between them, the invisible setting of the Top Wesselton round diamonds, with no visible gold in between each one, has resulted in a breathtaking bezel with an alluring, tactile quality and a super smooth finish.

The Jacob & Co. Brilliant Skeleton Jewelry timepiece is available in a limited edition of 101 individually numbered watches.

Posted on

Jacob and Co. Brilliant Skeleton Northern Lights

For more than a quarter of a century, Jacob & Co has created revolutionary timepieces and exquisite jewelry that have captivated celebrities and notables from the watchmaking world and dazzled fashion’s red carpets and cover shoots. With a unique talent for creating designs that are as innovative as they are spectacular, the company has grown into one of the most recognized luxury brands in timepieces and jewelry. Jacob and Co. Brilliant Skeleton Northern Lights
The 44 mm steel case of the Brilliant Northern Lights Skeleton is pavé set with 251 round diamonds (≈ 9.52ct.). The crown is set with 33 additional diamonds (≈ 0.2ct.).

closevolume_offADS
The mineral crystal dial is available in four colors: blue, green, red and yellow. The timepiece is fitted with the exclusive Jacob & Co. Skeleton Manual Winding Caliber JCAM01. Jacob and Co. Brilliant Skeleton Northern Lights

A satin strap with a tang buckle set with 76 round diamonds (≈10.30ct.) completes the piece.

Posted on

Jacob and Co. Brilliant Art Déco

The Jacob and Co. Brilliant Art Déco is an exquisite timepiece mixing the best of high jewelry and horology. This sumptuous masterpiece has a noble composition of 18 carats gold and diamonds, a treasure chest for the hypnotic mechanical sensual beauty of the hand-finished openwork Jacob & Co. JCAM05 Caliber.
Jacob & Co. is one of the few brands that has the legitimacy to create high and fine jewelry, as well as high-end watches.

The diamond and gemstones industry is a closed society, and it is really a relationship business. Sourcing the very best diamonds and gemstones depends on reputation and personal connections, and thankfully Jacob & Co. has solid, decades-long relationships.

As a result, Jacob and Co. Brilliant Art Déco has access to the very best sources of diamonds and gemstones from all over the world. Many of the gem-set timepieces, like the Brilliant pieces, require meticulous care in the choosing of stones for quality, cut, clarity, and matching color. For a piece like this Brilliant Art Deco Arlequino, this can take many months or years, depending on the exact colors needed.

Jacob & Co. is also an expert in the setting of these stones, working with the very best gem setters in the industry.
Skeletonizing is an age-old tradition in watchmaking. The challenge is to remove enough material from the movement to make it nearly transparent, without impacting its performance, precision, or robustness.

Jacob & Co.’s watchmakers have been skeletonizing movements for decades, so they understand exactly where and how much to remove, and the result is a nearly see-through movement, set up to maximize the beauty of this little engine on the wrist.

Underlying all this beauty lies the legendary timepiece workmanship for which Jacob and Co. Brilliant Art Déco is famous. The tourbillon was originally invented to be a single-axis, rotating cage secured from above as well as below to carry the regulating organ of a mechanical pocket watch for improved timekeeping performance. The version in the Brilliant Art Deco Arlequino presents this more than 225-year-old invention in a yet more spectacular way.

The one-minute tourbillon features a delicately decorated cage that encapsulates the balance wheel, hairspring, escape wheel and a number of other crucially important components. This open-worked cage not only features an elaborate web-pattern in its architecture, but allows for an unobstructed and full view at the ultimate refinement of its detailing and operation. It is a constellation of superbly finished components that, when assembled and fine-tuned expertly, allows the JCAM05 movement to keep accurate time throughout its 72-hour power reserve.

The movement uses sapphire crystal plates to make the movement even more transparent, and the bridges of this spectacular movement are set with 177 multi-colored sapphires and one brilliant-cut white diamond.
The 47mm 18K gold case, inner bezel, and crown of the Jacob and Co. Brilliant Art Déco Skeleton Collection is invisibly-set with baguette-cut sapphires (the crown has a rose-cut sapphire on the top), while the inner bezel is set with baguette-cut white diamonds. Covering the front and back of the timepieces are anti-reflective sapphire crystals, putting the beautifully skeletonized movements on full display.
The beauty of skeletonized watches is that there are no dials – instead the highest quality sapphire crystals expose the details of the movement, including the wheels, gears, balance, bridges, and mainspring barrel. The leaf-shaped hands in the center, indicating the hours and minutes, float over the mechanical splendor.

Posted on

Jacob and Co. Brilliant Watch Pendant

The Brilliant Pendant Watch collection brings together art, contemporary design, traditional high watchmaking, and bejeweled beauty to a women’s timepiece.

As the name suggests this collection of timepieces is designed to be worn as pendants, suspended from an 18K gold chain around the neck as a piece of jewelry. But this collection offers so much more. The highly polished 18K rose gold and diamond-set case houses an anthracite skeletonized movement, a product of both art and traditional high watchmaking craftsmanship.

The Brilliant Pendant Watch collection is a masterpiece of contemporary jewelry and timepiece design that combines the classic art of the skeleton watch with the jeweler’s skill of meticulous, invisible gem setting.
A skeleton movement, also known as “open-worked,” is one in which all the mechanical moving parts are visible. The “skeletonization” process involves the trimming of non-essential metal on the bridge, plate, wheel train or any other mechanical part of the watch, leaving only a bare skeleton of the movement required for functionality.

The exquisitely crafted skeletonized anthracite caliber JCAM01 manual winding movement for the Brilliant Pendant Watch collection is made of 150 components with high watchmaking finishes. Rose gold is used on the engraved bridges, gears, and a Roman numeral “XII” at 12 o’clock. The balance wheel is visible at 3 o’clock, adding to the artistic beauty of the finely crafted movement.
The highly polished 42.5mm 18K rose gold case of the Brilliant Pendant Watch collection has a bezel lined with 72 brilliant round diamonds. The crown above 12 o’clock is paved 31 brilliant diamonds. Sapphire crystal on the front and back of the watch provides a full view of the exquisitely crafted skeletonized movement.
Blued leaf hands for the hours and minutes glide across a sapphire crystal dial that provides an unobstructed view of the skeletonized anthracite caliber JCAM01 manual winding movement.

Posted on

Jacob & Co. Brilliant Pavé

With 761 diamonds adorning the case and dial, the Jacob & Co Grand Baguette Timepiece is one of the most astonishing examples of the diamond cutter and diamond setter’s art. This astonishing horological and gemological masterpiece presented an enormous challenge to realize. Horological gem setting is one of the most, if not the most, demanding branch of sertissage (the art of gem setting). Indeed the geometry of the case and dial place severe constraints on the geometry of each stone, and in a fully decorated timepiece like the Grand Baguette, there are many stones which must be cut and polished to extremely close tolerances in order to produce the unbroken, scintillating surface which is the gem-setter’s goal. Moreover, because each stone is in close proximity to its neighbors, each must be as perfectly matched as possible in terms of color, fire, and clarity in order for the timepiece to present a harmonious overall appearance – especially as each stone is in an invisible setting, which would make even the slightest error in shape or mismatch in color and clarity apparent.
The baguette cut also emphasizes the clarity, luster, and whiteness of a diamond but this same property can reveal even the slightest flaw, making the selection, cut, and matching of each stone even more crucial. The process of creating the Jacob & Co Grand Baguette was made even more difficult due to the unusual geometry of the case – the pentagonal configuration overall, as well as the different shapes and sizes of the surrounds enclosing the sub-dials, meant that an enormous range of shapes had to be cut and polished (the work is done by hand) and for each stone, a blueprint akin to an architect’s plan has to be created to ensure proper geometry and size.
Another tour-de force example of the gem-setter’s art, the Brilliant Skeleton Baguette watch combines the fine technique of openworking and horological gem setting. It is thanks to the movement’s unusual design, which incorporates a balance bridge which seems to hold the balance suspended in space, that this amazing timepiece is such a successful example of the art of openworking. In most skeletonized watches the basic design of the movement tends to make for a somewhat unharmonious result, but with the caliber JCAM01a the symmetry and graceful curves of the movement’s plates and bridges, as well as the use of the distinctive balance bridge at 6:00, make it a dramatically successful example of the art of openworking, in which both maximum transparency and a sensitivity to the fundamental architecture of the movement are essential. Surrounding and in dramatic contrast to the hand finished movement, with its meticulously polished and beveled plates and bridges, is a generous white gold case set with 357 baguette cut rubies. Even the crown is decorated with 12 baguette rubies as well as a single rose cut (a traditional, antique cut first used in the 16th century) ruby in the center of the crown.
Inside the Palatial Tourbillon Collection featuring three astonishingly beautiful and hypnotically fascinating tourbillons, the Palatial Tourbillon Minute Repeater adds to the visual dazzle of the tourbillon the musical function of a minute repeater mechanism through the translucent blued sapphire crystal The entire device, which is usually hidden away from view under the dial, is visible here – press the slide which arms and activates the repeater, and you’ll not only hear the hours, quarter hours, and minutes rung on two cathedral gongs, with all the charm of an haute horlogerie timepiece and a musical instrument combined – you’ll also see the incomparable mechanical dance of the complex system of racks, snails, and levers that bring to life the song of time.
With his usual spirit of committing craftsmanship to the service of beauty, Jacob & Co offers his new seductively feminine Brilliant Steel Collection : consisting of a range of timepieces of unsurpassed elegance, this family features a stainless steel case (32, 38 or 44 mm) adorned with round, brilliant cut diamonds, in full pavé or half-pavé versions, offered with either one or two rows of diamonds set into the case as well as a cornucopia of selections in dial executions. Mother-of-pearl is the basis for all the Brilliant Steel Collection dials, also combined with a rich variety of precious gem dial markers : yellow sapphire, orange sapphire, tsavorite and ruby. For lovers of the fire of brilliant cut diamonds in all their unadulterated glory, there is a full pavé diamond dial offering as well – the largest of the full pavé models, in 44 mm, is resplendent with 497 brilliant cut diamonds.
One of the most iconic of all watches for Jacob & Co is the famous Five Time Zones watch, which now comes with the Ghost version, using the latest innovations in electronics to create a dramatic and fascinating display of time around the world in a variety of colors. Twenty cities can be chosen for four of the five windows, while the fifth can be set to a local time of the user’s choosing. Most fitting for a world traveler’s watch, it has an internal GPS receiver which will, on demand, lock onto the global GPS satellite network and synchronize itself to the atomic clock controlled GPS network.

Posted on

Jacob & Co. X Supreme

Supreme’s new Fall/Winter 2020 collection has been revealed and a pair of very special watches are included. These new Supreme x Jacob & Co. Time Zone 40mm and 47mm watches are surely going to sought after by both watch collectors and fans of the Supreme brand. These watches come with the ability to read out four different timezones, and even have three of the subdials named for New York, Paris, and Tokyo. Surrounding the dial of the 40mm version are 52 white diamonds (~2.08cts), while the 47mm watch has 51 white diamonds (~3.06cts). Each comes with an alligator strap. You can see more of the collection by clicking the button below.
The Supreme x Jacob & Co. Time Zone watch comes in either 40mm and 47mm sizes. The stainless steel four-time zone watch features a lacquered dial with custom logo inlay, an interchangeable stainless steel bezel set with 51 white diamonds (~ 3.06cts), and an alligator strap with stainless steel logo buckle. This is a new take on one of Jacob’s signature pieces from the ’90s.
Supreme is making waves by tackling the world of watchmaking, and unveiling its new collaboration with Jacob & Co. X Supreme Two resolutely street-inspired watches with a Fuck Em mantra, and certainly chic with their 50 diamonds — a product of the two houses’ worlds clashing.
Jacob & Co.The result? Two limited edition watches, stamped with the streetwear brand’s signatures, and equipped with the American watchmaker’s expertise.The Jacob & Co. X Supreme Available in 40mm and 47mm, each of these watches features 51 or 52 diamonds, depending on their size, an alligator leather strap, and the Supremelogo on its face. As a bonus, these collector gems feature 4 time zones: your own, Tokyo, Paris, and New York. To banish jet lag, and always be in transit to the four corners of the earth. Now, you only have to choose between the all-black version, or the red strap and color-splashed face.
After collaborating on an uber-affordable Timex last season, Supreme’s gone in the opposite direction and is pointing itself directly at the world of luxury timepieces. A series of jackets feature a print of a dial clearly inspired by Rolex’s Cosmograph Daytona. Supreme takes a couple liberties with its version of the watch’s face: it says “Supreme Perpetual” instead of “Oyster Perpetual” and the bottom line reads “Fuck Em,” which would certainly be a hard left turn for an official Rolex. (The phrase does also appear on a Rolex Submariner that Supreme customized in 2013, although that wasn’t an official partnership.) The design appears again on a 12-inch plate the hottest menswear status symbol in the game! The literal jewel of the latest watch-centric Supreme releases, though, is a collaboration with Jacob & Co. The jeweler’s Five Time Zone watch now includes the Supreme box logo and, of course, a “Fuck Em” alongside more than 50 white diamonds.

Posted on

Jacob and Co. Quenttin

Jacob & Co. deserves a lot of respect (and thanks) from the watch industry. Founder Jacob “the Jeweler” Arabo is one of the modern luxury watch industry’s most courageous people. No doubt many of Jacob & Co.’s design are polarizing in terms of taste, yet the brand heralded in a new era of risk taking and visual assertion that shocked many of the luxury world’s conservative members.
The post Jacob & Co. era is rich with what can easily be described as “crazy” designs — compared to what you might have seen 20 years ago. Jacob & Co. not only pushed boundaries on bold designs, but also with luxury itself. While the brand is most well known for colorful jewelry watch creations, the less well-known side of the brand has fascinating mechanical complications designed to prove Jacob & Co.’s legitimacy on a variety of fronts. This high-end mechanical watch family from Jacob & Co. is typified by the simply named Jacob & Co. Quenttin watches .

While the watch industry understood the technical purpose of the Quenttin when it arrived in 2006, the actual effect of the watch was not understood until years later. Jacob wanted a watch that would be at the peak of technological sophistication, but also one that would capture the attention and imagination of all people who saw it.

Collaborating with then existing exotic watch movement maker BNB Concept, the movement of the Quenttin was a particular challenge to devise. It was to have the world’s longest power reserve in a wrist watch. Jacob wanted the movement to have a power reserve of a full month, it needed to have a tourbillion, as well as other complex components. It was also necessary for it to be visually engaging with mechanical elements totally visible to the. Jacob & Co. even managed to throw in an indicator for the date.
The result was a machine that looked more at home in a car than in a watch. The concept of the movement was so interesting, and many others have since borrowed design elements from the design. At the time of its release, the Quenttin was engaged in a “race to market” with Cabestan (who had a similar piece) that Jacob & Co. beat. Most of the Quenttin’s movement is vertically aligned, including the drums that slowly move to tell the time, the side-mounted tourbillion (visible through a side window), as well as the seven mainspring barrels that are responsible for the full 31 days of movement power reserve.

Jacob & Co. didn’t so much want to design a case for the watch, as must as they did a “house” for the movement. The large rectangular watch case holds the movement adequately and is offered in an assortment of color metals such as 18-karat white or rose gold. Over the exposed movement is a large sapphire crystal.

There is another interesting case for the Jacob & Co. Quenttin watches , and that is the box the watch comes in. It also doubles as a winder. Using a hand-movement activated trigger, swiping your plam across part of the case will open it. You can then place the Quenttin watch into a special cradle that serves another purpose — to wind it. The seven mainspring barrels require about 200 turns to be fully wound. As such, the Quenttin box features an automatic winding system to mechanically wind the watch when the winding system is activated. Though there is a fold out key which allows you to wind the watch by hand.

In 18-karat white or rose gold or magnesium, the Quenttin case is massive being 47-mm wide, 56-mm tall, and 21.5-mm thick. Only 135 Jacob & Co. Quenttin watches were ever destined to be made.

Posted on

Jacob & Co. Ghost

For me the most interesting watch I saw from Jacob & Co. this year was this Ghost G5 timepiece. The Ghost is a brand new collection for 2011 designed by Jacques Fournier (Horology Design Ltd.) in cooperation with Yvan Arpa who is now a figure at Jacob & Co. The Ghost will comes in a few forms and is called the G5 and GT5 as well (Ghost 5 time zones). The Ghost has a new five-sided case that is strange at first but ends up looking rather nice on the wrist. I like this watch a lot more than I might expect if you just described it to me on paper.

This 47mm wide case shows up on two other new for 2011 Jacob & Co. timepieces called the Grand and the Global. All the new “G” watches have quartz movements. The Grand and the Global have analog faces while the Ghost has a slick new type of digital LCD screen that I haven’t experienced before.
Jacob & Co. offers the Ghost in a number of styles and decoration. For example, this model is in a PVD steel case with a baguette diamond decorated bezel. There are other diamond bezels available, as well as polished steel cases. Looks like gold might also be available as this prototype has some gold around the pushers. While it is almost heresy to think about a Jacob & Co. watch sans-diamonds, there is a carbon fiber bezel as well that looks pretty cool and sporty. Be sure to realize that the diamond bezel version models are super pricey.

The big size of the watch isn’t actually too bad. The 47mm wide case is rather comfortable and the unorthodox design draws attention in the right way. The brand really designed something that is both blingy and techie at the same time – which is something exceedingly hard to do much of the time.
OK, so what is the deal with the movement? It has six screens, but the center one is just the Jacob & Co logo. Five of those screens are multi-functional screens that can show a range of information. That means you can see the time, calendar, chronograph, and other functions. I am not sure everything it does and to be honest you need to consult with the manual to figure it all out. To save battery life the screens are blank unless activated – due to the intense backlighting. The trade off is a range of color options. According to Jacob & Co. the screens are able to show 32 different colors. Not just that, but you can have the watch just keep changing colors – even while the screens are turned on. It is really rather quite disco if I may say.
The Ghost is fun, that pretty much sums it up. People are gonna complain about the strange shape and the screens that go from pink to purple to green to red. Jacob’s Jacob probably just sits back and smiles. He thrives off the high-end, high-risk, and highly original. The Ghost is really a timepiece that brand can call their own – and I swear I do want to wear one.

Posted on

Jacob and Co. Five Time Zone

The year 2015 is almost at a close, and we’d like to help wrap it up with an Replica watch buying gift guide – done, once again, a little bit differently. As a publication that tends to help consumers make choices about watches they want to purchase, we dislike the idea of arbitrarily limiting your buying options to a few timepieces that we feel just narrowly beat out others in any given list. So for that reason, we try to stay away from more randomly assorted gift guides that, frankly, also bore us to create. Jacob & Co watches

What we’ve done for this holiday season’s gift guide idea was to ask various members of the Jacob & Co watches team to mention the first watch that comes to mind when presented with a particular question. For example, we asked the question, “What watch would you wear to impress Vladimir Putin?” (a known watch buff and all-around leader of Russia). Each of the questions we asked called for a different type of watch, and we included some of our favorite responses from the aBlogtoWatch team. It’s just a little way of getting into our watch nerd heads and having fun during the holiday season (where, apparently, rest and relaxation is but a myth).
Whether your budget for watch buying is modest or prodigious, you’ll find some interesting timepieces here in each (perhaps unexpected) category that the aBlogtoWatch team feels are worth mentioning – from those suitable for very ordinary occasions to those which might only occur in our fantasies. Please offer your own choices in the comments below if you feel you have some watch choice responses to compliment our own.
Let’s start with the trusty everyday watch, something you can knock around and not worry too much about because it isn’t that expensive. With that in mind, it’s also got to be designed well, reliable, and say something about the wearer. Here are our top picks for the “beater watch” category.
Moving on from an everyday beater watch, we take a look at 4 picks for watches that even a massively wealthy oligarch would give a second look. Vlad’s a well-known watch collector, and we think he would happily add these to his shiny, fabulously ornate watch safe.
There is no shortage of flashy watches and there’s no shortage of highly complicated watches out there. What if you want both, though? Well, we decided to think up 4 watches that we think will get you both attention and horological admiration.

Posted on

Jacob and Co Astronomia Casino

Drake‘s latest wristwatch purchase arrives in the form of the Replica Jacob & Co. Astronomia Casino . The complicated timepiece features a four-arm setup: one arm contains the double-axis tourbillon, one a magnesium lacquered globe, the other a Roman numeral time display, and lastly, an arm that sees a 1ct 288-facet Jacob-cut diamond — this all sits in a massive 28mm-thick 18K rose gold/sapphire crystal case.

All four arms sit atop the highlight of the watch — a fully-working roulette table that’s complete with a ceramic ball. Priced at $300 USD, this Replica Jacob & Co. Astronomia Casino is sure to separate Drake from the plethora of Patek Philippe Nautilus watches worn by his peers.
Luxury watches are not just about telling the time anymore. A case in point, acclaimed timepiece and diamond jewelry house Replica Jacob & Co. Astronomia Casino , which features a fully-operational miniature roulette wheel beneath the watch’s sapphire crystal dome case. The Astronomia Casino’s wheel, rendered in a spectacular array of green, red, and black enamel with mahogany inlays, is set in motion by a button at the eight o’clock position (which also winds the power reserve for the animation).

This exceptional timepiece, the latest in Jacob & Co.’s signature Astronomia collection of celestial-themed timepieces, can be personalized with a mother of pearl insert placed by Jacob & Co. craftsmen on the owner’s lucky number.
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 double-axis tourbillon of the Replica Jacob & Co. Astronomia Casino is at the forefront of modern watchmaking. The flying tourbillon’s delicately decorated cage encapsulates the balance wheel, hairspring, escape wheel and a number of other crucially important components. Characterized by this open-worked cage, this outstanding tourbillon rotates on two axes simultaneously. It is a constellation of superbly finished components that, when assembled and fine-tuned expertly, allows the JCAM10 to keep 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 is made possible by the 10-minute, four-arm rotating platform of the Astronomia Tourbillon. 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.
Never before has there been a grand complication timepiece with a roulette wheel that spins, allowing owners to play their favorite game of chance at any time. Though the Astronomia Casino is simple to use and enjoy, the technical solutions to actually make it work seamlessly took more than a year of development time.

Separated from the movement by a sapphire crystal, the ceramic ball can bounce with abandon with no danger of impacting the functioning of the timepiece.
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.