Watch crystal: Insights and Tips

When talking about watches, I think we all agree that the watch movement is the most important part. But what’s next? For me, it would be the case and watch glass since it protects the dial and movement while also adding a subtle beauty to the design. That is why, I would like to provide you with some insights into watch glasses in this week’s Von Doren blog post.


There are 3 types of watch glasses, namely Acrylic Glass, Mineral Glass and Sapphire Crystal and they all have their own pros and cons.

Different types of glasses - Von Doren

Acrylic glass, the cheapest one among the three types, was widely used up to the 1980s. This kind of glass is actually plastic so it is flexible, transparent and very light. It is hard to break but gets scratched easily. Fortunately, the scratches can be easily buffed. Watchmakers usually use acrylic glass to make cheap watches, especially children’s watches.

The disadvantages of acrylic glass has pushed many manufacturers to move to Mineral Glass. Mineral glass is the most common type of watch glass to be found in the market right now. It ranks 5 out of 10 on Mohs hardness scale and is known to be used in glass windows. It gets hardened by heat and coated with a hardening material. This production process makes mineral glass more scratch- and impact –resistant than acrylic glass. However, under extreme hot and cold conditions, mineral glass may crack or shatter.

The third and also the most desirable glass type is Sapphire Crystal. Its outstanding resistance and clarity makes it a perfect choice for premium watches. Sapphire, rated 9 out of 10 on Mohs hardness scale, is the second hardest substance on Earth. It is believed that only diamond and other sapphires can scratch sapphire. In the watch industry, it is common to use synthetic sapphire which is constructed of crystallized aluminum oxide. Synthetic sapphire does not have color but has the same physical attributes as the natural sapphire. Tough as it is, sapphire crystal requires delicate work during milling and cutting.