Selecting the Materials: Sapphire Glass

January 11 2016


Our new series of articles on the individual, materials that make up our products kicks off with the scratch-resistant, virtually indestructable window to telling the time on your Bulbul watch that is sapphire glass. Part informative customer service, part a fielding of some of your questions regarding our price range, Selecting the Materials will delve into the nitty gritty nuances and properties of sapphire glass, movement, leather and steel.

For the moment, however, our efforts will remain firmly focused on the glass; First of all, there are a number of benefits to using sapphire crystal on your timepiece. Generally speaking, It’s the go-to material for premium watches. Apart from the fact that It’s the most expensive type of crystal, it’s three times harder than mineral crystal. Moreover, It is made of an extremely durable synthetic material that makes it shatterproof and scratch resistant. It isn’t 100% scratch-free – very few materials are - but this particular form of crystal is actually second only to diamond in its hardness, making it very durable indeed. Most often grown in cylindrical sticks known as boules, it’s slow, expensive and energy-intensive to produce, all of which adds to the overall cost of the high-grade material.


As some of the jewelry enthusiasts among you will know, sapphires in their natural form are most often used in jewellery. The colour in these gemstones are caused by impurities such as iron, titanium, chromium, copper and magnesium, but synthetically created sapphire is clear and colourless, because it contains no impurities.

Sapphire crystal is also utilized in a wide range of other products, such as airplane windows and laser-based applications (radio therapy, proton therapy, accelerator physics, nuclear physics), but the most common implementation is still in premium watch displays that cover a Swiss movement.  


As we mentioned in the introductory post, we felt that only the best materials available would suffice if the material durability of our products was to live up to the aesthetic sustainability that our design partners at KiBiSi set out for in the beginning of the design process.

Watch this space for more information on the individual materials. Next up: Steel mesh bands from Pforzheim-based manufacturer, Vollmer.

- The Bulbul Team