Mineral, hesalite, or sapphire? - Types of watch crystals
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Mineral, hesalite, or sapphire? - Types of watch crystals
There are numerous features that we have to consider while choosing a watch adequate to our needs and expectations, including types of movements, straps, or general appearance. Another attribute, which determines the resistance to external conditions, is watch crystal. Why is this small and transparent element of a dial so important?
The Mohs scale - find out which watch crystal is the best
The Mohs scale is used to determine the hardness and scratch resistance of various minerals. Scale values from 1 to 10, where one means low resistance and ten means that the object can be scratched only by a diamond, help to compare each type of watch crystal, in order to choose one that meets our expectations. Let’s find out which one is the best for you!
Hesalite crystal - 1 in the Mohs scale of mineral hardness
This type of watch glass has the lowest resistance in comparison with other kinds - in the Mohs scale, it measures only 1-2 points. It is made out of hardened and clear polypropylene. Often, it is simply called “a plastic” crystal. Even though it can be very easily scratched, it has some advantages. This type of crystal can be polished to remove small scratches and due to its high flexibility, it is not that easy to chip or shatter hesalite glass, comparing with other types. Moreover, watches with plastic crystal are way cheaper than watches with mineral or sapphire crystal, due to lower production costs. Among the most popular watches with hesalite crystal, we can recommend Casio Sport series, stylish Zeppelin watches and comfortable Timex Ironman.
Mineral crystal - durable and affordable
It is definitely the most popular type of crystal used in wristwatches. In the Mohs scale, it measures 4, which means scratch resistance at medium level. Due to its flexibility, it can not be shattered that easily as e.g. sapphire glass. Production costs of mineral crystal are adequately higher. This type of glass can not also be polished as easily as plastic crystals. We can find mineral crystal in medium to higher-price watches. It is an optimal solution for everyday watches.
Hardened mineral crystal (Hardlex)
This type of dial protection is simply strengthened, hardened mineral crystal. Because of that, glass doesn’t lose its flexibility and it is more scratch resistant than regular mineral crystal. Moreover, it is not that easy to shatter. This type of glass is often used in sport watches, especially in those for divers. Hardlex glass is easy to find in brands like Seiko, Vostok Europe, Festina, and Adriatica.
Sapphire crystal - synthetic glass with the highest hardness
This glass has the highest scratch resistance possible. This extraordinary hardness is the effect of using corundum - a mineral responsible for forming synthetic sapphire. It is one of the hardest materials on the planet. It measures 9 in the Mohs scale of mineral hardness, which means it can be scratched only by a diamond. This guarantees the best protection possible, and we can be sure that a watch with sapphire glass will look brand new even after many years and it won’t lose its transparency. The only drawback is its fragility, which means it is easy to shatter. Brands that often use sapphire crystal are: Adriatica, Atlantic, Doxa and Roamer.
Can watch crystal be problematic?
Long-term use of watch can cause some problems sooner or later. Scratches or shattering are the most common issues that almost every watch owner must deal with. But why? It all depends on the hardness of used material. Softer glass equals more scratches. On the other hand, it is way more flexible than the hard glass, which means it rarely breaks. That is why it is so frequently used in sport watches. Sapphire crystals are scratch resistant, however, due to its slight flexibility, the risk of shattering is much bigger.
Which one will you choose?
While choosing a watch, it is important to consider your expectations. If you need a simple, everyday watch, the best choice would be mineral crystal. If you are looking for a comfortable sport watch - try hesalite glass, especially if you love swimming and diving, or hardened mineral crystal. However, if you dream about elegant and durable watch, then sapphire crystal is what you are looking for.
