If you own a watch, chances are that you have not given much thought to what type of glass is used to protect the dial. However, the type of glass your watch has can make a huge difference on how durable your watch is, the aesthetics of it, and how expensive this type of watch can be. There are three different types of watch glass: acrylic crystal glass, mineral crystal glass, and sapphire crystal glass. Each of these is unique and comes with its own advantages and disadvantages. If you are eager to learn more, keep reading.
Acrylic Crystal Glass
If you ever owned a watch as a kid, chances are that it was made with acrylic crystal glass, also known as Plexiglass. Many watchmakers choose this type of glass to make children’s watches because of the fact that it’s actually made out of plastic and therefore durable and flexible. Although this type of glass is hard to break, it is prone to being scratched up, which can happen a lot if a child is wearing the watch. Luckily, these scratches can easily be polished away.
Acrylic crystal glass is less expensive than other types of watch glass, which means that it also keeps the price of the watch low as well. This type of glass hasn’t been used much since the 1980s, but ironically may sometimes be used to make “retro”-style watches.
The advantages of acrylic crystal glass are that it makes your watch more durable and cost-effective, while a disadvantage is that it tends to scratch easily and can be rather cheap looking at times.
Mineral Crystal Glass
These days, mineral crystal glass is the most commonly used form of watch glass. This type of glass is created by hardening it with heat and then topping it off with another coat of hardening material. Mineral crystal glass is much harder and more durable than acrylic crystal glass, which explains why it’s so popular. In fact, this type of glass can be found in most mid-range designer watches.
Despite being durable for the most part, this type of glass is known to shatter under extreme hot or cold conditions. One of the disadvantages to this type of watch glass is that if it were to be damaged, it would be nearly impossible to repair as you would need a replacement crystal altogether.
Sapphire Crystal Glass
This type of watch glass is considered premium due to the fact that it’s made out of the second hardest material on Earth. These crystals are found in luxury watches so you can expect to pay a pretty penny for them. However, sapphire crystal glass is scratch-proof and won’t crack or break, which may make the cost worthwhile. Interestingly enough, the only thing that can scratch a sapphire crystal glass is either another sapphire or a diamond.
Despite the name, sapphire crystal glass is not actually made from natural sapphires but is actually a synthetic compound with some of the same properties. Sapphire crystal glass isn’t technically glass but is instead transparent crystallized aluminum oxide.
Because of their durability, watches made with this type of glass are military grade and used by people who work manual jobs or are around areas where they could potentially drop their watches. Some of the disadvantages of sapphire crystal glass include the fact that it can be incredibly pricey, and that repairs are generally impossible if it should be damaged in any way.
How to Tell Between the Different Types of Crystal?
When you set out to buy a new watch, you are going to want to know how to tell apart the different types of crystal. The good news is that these three different types of glass are so unique that they aren’t too hard to tell apart.
Acrylic, for example, pretty much feels like plastic when you touch it. It turns warm, as opposed to sapphire and mineral, which stay cold to the touch. Another way to tell between these types of glass, particularly between mineral and sapphire, is by placing a drop of water on top of the glass. The water drop will stay in the same place if you’re dealing with sapphire, while the water will fall down the side when dropped onto mineral.
You can also tell the types of glass apart using sound. Tap your fingernail on the glass and listen to the sound that it makes. If the sound is solid and low, chances are that you’re looking at sapphire. If the sound is high in tone, on the other hand, it’s mineral.
Perhaps the most obvious way to tell apart these types of glass is price. Acrylic is going to be the least expensive type of watch glass, while sapphire will be the most expensive.