When buying a watch it is very important to assess what type of crystal it has. There are certain advantages and disadvantages of each material. However, as you'll see later on, there are reasons why some materials are cheap and are used in low quality watches and others are quite expensive and are used exclusively in high quality watches.
Normally we say that there are three different materials used for watch glass: acrylic, mineral glass and sapphire crystal. And in this article we'll go through each of them. But it's not uncommon that you'll also see names such as Hardlex, Lucite or Sapphlex. These are usually just variations and brand names of earlier mentioned core materials. It would take quite some time to name them all but actually there's no need for that. Once you know properties of the main material, you'll easily be able to access what is hiding behind the fancy name.
Even though acrylic is called glass in this case, actually it's not. It's a piece of plastic. And it's super cheap to manufacture. As you might have guessed this take its toll on quality. Acrylic is susceptible to scratches. When using your watch daily you'll quickly notice scratches on the surface. The bright side is that you can polish them out quite easily. The down side is that you'd have to do it quite often. However, if case you need to replace it, again it's cheap. Another advantage is that it is very shatter-resistant. On the other hand, acrylic usually indicates that the watch is cheap and low-quality.
If you need a new watch and you are on a budget, acrylic glass can be an option. Also acrylic is quite often used in kids' watches - this will save you a headache and money when after a day full of adventures your offspring come home with scratched watch surface.
Absolute majority of the watches will fall under this category. Price / quality ratio makes this option very attractive for manufacturers. And this is actually glass. Nowadays, mineral glass is usually hardened. It simply means that it was exposed to high heat and thus became even more scratch-resistant.
Advantages over acrylic? Incomparable improvement in scratch resistance. It doesn't mean that the watch cannot be scratched. But in most cases you'll be very happy that you've opted for a watch with a mineral glass instead of acrylic.
Downsides? It's more expensive and this will be reflected in the final price. Over the years you'll get a scratch or two, it's almost unavoidable. And most likely you won't be able to do anything about it. Sometimes it's even impossible to change the glass. So you'll have to live with these scratches. And finally, mineral glass shatters quicker than acrylic.
As you can see, there are quite a few disadvantages. Nevertheless, you will still want to go for a mineral glass instead of acrylic in 999 cases out of 1,000.
This is the material that is used in most expensive watches. Not in all of them but in absolute majority. It is also the most expensive material. So what are the benefits of it? There's only one but the most important - it's almost impossible to scratch it. Sapphire crystal ranks 9 out of 10 on Mohs hardness scale. Above it sits only diamond. So if you are not surrounded by diamonds in your daily life your watch should be safe and sound.
You might have a question in your head right now: "aren't sapphires blue?". Yes, they are. But they can also have other hues - yellow, purple, green, violet, brown, orange, you name it. This happens because of trace elements such as iron, copper and others. Different trace element or their combination will give a different hue.
So how is it that the sapphire crystal in watches is transparent and doesn't have any hue? For this we have to thank French chemist Auguste Verneuil who in 1902 discovered how to create a synthetic sapphire crystal. Since it's synthetic, manufacturer can make it transparent. Simple, right?
However, sapphire crystal has its Achilles heel. Even though it's extremely scratch-resistant but it shatters relatively easy compared to other two materials. But hey, don't get anxious - relatively easy does not mean easily. It’s just a warning for you not to be surprised if you see that it's shattered after a strong impact.
And there's another downside - repair of a shattered sapphire crystal can be extremely expensive, especially for luxury brand watches. Keep in mind that watches from smaller brands might not even be repairable at all. So if you decide to go for a smaller brand watch make sure to ask them whether it would be possible to replace a broken sapphire crystal.
But don't let these negative aspects make you skeptical. Sapphire crystal is a superior material when it comes to protecting your watch. Even though it might be more expensive but in our opinion it's totally worth the investment. It's very esthetically unappealing when you glance at a watch and see that there's a scratch on its face.
Therefore we opted to use a sapphire crystal in all of our watch models. And yes, in case you shatter your sapphire crystal in SGS watch, we do repair it!