Review: Hublot Big Bang Sapphire

The steel and gold used to make watches are sourced from the ground and refined into a raw material, which is then shaped and finished into the final product. All pretty standard, pretty normal. But what if you could grow your watch instead?

Sapphire, natural sapphire, is formed over millions of years as a crystalline variety of aluminium oxide called corundum, tinted blue with a dash of iron and titanium—or red with chromium, making the corundum a ruby. It’s an igneous mineral, in that it has formed through heat from the magma deep within the Earth’s core, forming crystals as it cools that emerge as the second most popular gemstone after diamond.

As well as looking pretty, sapphire has a neat trick up its sleeve: second to diamond, it’s the hardest naturally occurring material in the world. Hardness specifically refers to scratch resistance, the ability to withstand deformation—perfect for protective screens.

But manufacturing a protective screen from natural sapphire would be next to impossible and prohibitively expensive—not least because colourless sapphires with no trace elements are incredibly rare. What if there was another way?

There is, and it can be found in the laboratory. Using aluminium oxide powder, readily available and mined in large quantities, and a furnace cranked up to half the temperature of the surface of the sun, sapphires can be artificially grown.

The secret is turning the aluminium oxide powder into a crystal, and that’s where the heat comes in, replicating the igneous conditions found millions of years ago within a single use molybdenum crucible. But there’s one last trick before the mix is ready to go, one that might take you back to your childhood.

A piece of sapphire, known as a seed, is added to the crucible. Once the aluminium oxide has melted, it begins to form as crystals around the seed, just like the grow-your-own crystal kits you had when you were young.

What emerges is a 200kg solid, colourless sapphire, ripe and ready to be diamond-cut into screens, aircraft windows, watch crystals—and of course this, the Hublot Big Bang Unico Sapphire.

With a block of raw sapphire in hand, the process of converting it into a watch presents a particular problem: remember, this is the second hardest naturally occurring material in the world. Not too much of an issue for simple shapes like flats screens, which can be cut with steel wire in a bath of diamond paste, but for something as complicated as a case, the machining time goes up exponentially.

That doesn’t seem to have deterred Hublot, however, the brand having seen fit to furnish the Big Bang Unico Sapphire with a sapphire bezel, case and case back, held together and fitted with titanium screws and accessories. Each sapphire component starts life as a solid block, the long, slow, tedious process of reducing it into what’s left here happening one diamond-polished surface at a time.

What results is a £50,000 evolution of the classic Swatch Jellyfish, an all-out, budget-be-damned experiment in making the ultimate transparent watch. It’s kind of eerie to behold, its heart visibly beating away inside like it’s some kind of cave-dwelling, ghost-like creature that’s never seen the sun.

Given this Big Bang’s translucency, Hublot has seen fit to furnish it with the brand’s in-house Unico movement, a 330-part flyback chronograph with 72 hours of power reserve. It’s built around an architecture perfectly suited to the transparent resin dial, the chronograph column wheel and reset mechanism visible from the front rather than, as is traditional, the back.

The semi-transparent rubber strap completes the hyper-Swatch appearance, tightly binding the sapphire watch to the wrist. It wouldn’t normally be prudent to mention that it has a deployant clasp, but when a watch is as expensive and brittle—the trade-off for hardness—as this, it’s a feature to be grateful for.

Hublot doesn’t exactly command the respect of every watch enthusiast, but it’s hard not to be taken in by the visual complexity and sheer audacity of a watch made from sapphire. It presents a uniquely candid insight into the construction of a watch, from the outer case all the way into the very movement, and for that it should be applauded. Just don’t drop it.

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