In 2016, Hublot revolutionized sapphire usage in traditional horology by launching Big Bang Unico Sapphire. In order to realize this extra-ordinary mechanical timepiece, Hublot cut a sapphire case on an unprecedented scale, mastering a complex material, which is both ultra-resistant and totally “invisible” thanks to its transparency. Hublot has now fused sapphire and metals to create a Big Bang case in blue sapphire — marking the first time this colour sapphire has been used in watchmaking.
While coloured synthetic sapphires have been in existence since 1902, when they were invented by the French chemist Auguste Victor Louis Verneuil, melting sapphire is a complex and unpredictable process. Because its crystallisation process is unstable, it is difficult to obtain similarly coloured sapphires, even if they are produced simultaneously. Furthermore, bubbles and cracks can appear in the material, making the end result unsuitable for producing Big Bang cases.
But the main challenge is in the size. Thus far, no coloured sapphires exceeding 2 kg have been produced. However, Hublot has now gone beyond this threshold. By pushing the limits of engineering and chemistry, it has developed a sophisticated and costly process that has resulted in the successful production of a large, transparent sapphire of perfectly uniform colour. Hublot melted iron (Fe) with aluminium oxide. The result is a coloured sapphire that retains all the original properties of a material which is ultra-scratch resistant, completely transparent and among the hardest in existence. The innovation extends to the colour — the first blue sapphire in the history of watchmaking.
Case middle, bezel and case back cut from blocks of blue coloured sapphire. Flange, indices, Arabic numerals and hour/minute hands toned to match the colour of the sapphire, through contrast revealing the mechanism of the Unico HUB124 proprietary movement and its column wheel on the dial side.
Hublot has also designed a series of 250 pieces in red sapphire by heating aluminium oxide (Al2O3) — the raw material for sapphire — with a transition metal, chromium (Cr), at a temperature of between 2000 and 2050 degrees Celsius.
Model: BIG BANG UNICO SAPPHIRE
411.JL.4809.RT (Blue Sapphire) – Limited to 250 pieces
411.JR.4901.RT (Red Sapphire) – Limited to 250 pieces
Material: Polished blue or polished red sapphire crystal
Water Resistance: 5 ATM (50m)
Bezel: Polished blue or polished red sapphire crystal with 6 H-shaped Titanium (Blue) or black-plated Titanium (Red) screws
Crystal: Sapphire with anti-reflective treatment
Case back: Polished blue or polished red sapphire crystal with sapphire crystal
Crown and pushers: Satin-finished titanium (Blue) or satin-finished black-plated Titanium (Red)
Titanium (Blue) or black-plated Titanium (Red) screws
Polished and smoked transparent composite resin skeleton dial and appliques with blue or red luminescent
Satin-finished hands with blue luminescent (Blue Sapphire)
Black lacquered hands with red luminescent (Red Sapphire)
HUB1242, UNICO manufacture self-winding chronograph flyback movement with column wheel
Date Calendar display at 3.00
Number of components 330 (38 jewels)
Frequency 4 Hz (28’800 A/h)
Power reserve 72 Hours
Blue transparent structured lined straps (Blue Sapphire)
Smoked transparent structured lined straps (Red Sapphire)
Titanium deployant buckle clasp (Blue Sapphire)
Black ceramic and black-plated titanium deployant buckle clasp (Red Sapphire)