Sapphire versus mineral glass
April 22, 2017 Mathias Ericson
In Watch Specifications

The glass of the watch is a major aspect of a timepiece. There are two main types of glass used on watches, sapphire and mineral. Today the journal will cover the difference between these two as well as dive into what glass we use and why.

How to tell the difference

At first sight it is hard to tell the difference between what type of glass a watch utilizes. But after some everyday use you will be able to tell the difference without thinking twice, why you might ask? Well long story short it is because mineral glass scratches very easily while sapphire is almost uncatchable. This is because the hardness of sapphire, a material that measures extremely high on a scale for hardness called Mohs.

The only drawback of the hardness of the sapphire is that is shatters more easily than mineral glass. This is tested by dropping a steel ball on each type of glass from varying heights until it breaks, this makes it possible to calculate the total amount of energy needed to break the glass. So, on this scale mineral glass is actually a bit superior compared to sapphire glass. But let us be honest, it is not often you are in a scenario like the testing, for example having a car backing over your watch. While exposing the glass to things that can scratch the surface is part of everyday life as a watch-owner.

It is also a common saying that mineral glass looks cheaper in the way it reflects light compared to sapphire. Although this has not been tested and is probably not that easy to conclude. With this said, we still consider some part of it to be true.

What about NorthTwentytwo?

At NorthTwentytwo we want to create timepieces that truly lasts decades, both regarding design and function. This means we only use the best materials to craft our vision. Our choice of glass is always sapphire. Let us elaborate! A watch with glass that scratches after only a few weeks of usage is, according to us, not good investment. We want our watches to look as good as new for years to come when it comes to the finish of the glass, so scratches are not something you will find on a NorthTwentytwo watch!

If we look more specifically at our models and what types of glass we use it goes like follows. All Nord collection watches are fitted with flat sapphire crystal glass and all Arkipelag collection watches are fitted with dome sapphire crystal glass.

As usual, if you have suggestions for future journals or any questions about the sapphire or mineral glass do not hesitate to comment below or email us at info@n22.se.

Comment (1)

  1. Richard 4 weeks ago

    Hi,

    Thanks for this tips about Sapphire vs Mineral glass.
    For many years, I know the difference about hardness but I’ve learned something about the shattering.

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