Believe it or not, there’s a lot of discussion surrounding the types of materials used for protecting the face of a watch. There are different kinds of glass with different capabilities. If you’re a watch enthusiast, this will be of interest to you. This article will discuss whether or not different materials make a difference.
If you’re on the fence about a watch purchase, this will help you decide. If you’re not sure what sapphire crystal is, or you’ve heard of something called Hardlex but you don’t know what that means, you’re in the best place!
As you’ll probably already know, watch glass is that round (or square, whatever shape the face is) piece of clear material that covers the watch dial. It’s there to protect it from impact. It can also be used as a magnifier for a specific component, say the day/date window, for example. If you see one of these very small magnifying sections, this is called a Cyclops lens. Your first fun fact!
So, now you’ve learned the first thing: what watch glass actually is and what it does. Now it’s time to walk through the types of watch glass in detail. This list goes from the most fragile to the most durable.
Acrylic is the most fragile of all the types of watch glass used. This is because really, it’s plastic. Not real glass. It’s cost-effective to manufacture and as a result, it’s weak.
You will most commonly find acrylic glass on budget watches. Lower-end brands like Lorus or Timex commonly use this material on their sub $100 watches.
You’ll be surprised to find acrylic on some higer-end timepieces, but it does happen. Junghans, for example, use a material known as ‘plexiglass’ which is a type of acrylic with a fancy name. You’ll see terms like ‘perspex’, ‘acrylite’ and ‘lucite’ on the spec. If you do, now you know what it is.
Acrylic is lightweight, which is not a bad thing. If you’re in the market for a thin or weightless watch, an acrylic glass one will be an advantage, so don’t rule it out.
It’s usually seen on children’s watches not for the durability, but the likelihood of being replaced is high and therefore the cost to do so isn’t going to break the bank for a parent.
Advantages: It’s cheap to make, easy and cost-effective to replace, doesn’t weigh the watch down. It’s also easy to wipe off scratches.
Disadvantages: Looks as expensive as it is and is fragile.
Mineral crystal is the most commonly-seen glass on a watch. That is, if you’re going for a mid-range price tag. It’s made with an industry-standard tempered glass which derives from silica. This makes the mineral crystal better resistant to scratches. It’s generally cost-effective to make so this is why you see it most often. It’s not 100% scratch-proof, though. Over a few years, it will eventually pick up the odd mark. To fix this, you would need to get it serviced or send it back to the watchmaker who would be able to inspect it and tell you if it’s worthwhile buffing or replacing it.
Some watches with mineral crystal have a coating that makes it anti-reflective. It’s also called anti-glare or simply, AR.
Anti-reflective coating is usually done to enhance sports watches to enable good readability in poor lighting conditions. It can give a clearer view of the face which means less strain for the wearer. It also gives the look a more polished finish, meaning it looks more expensive.
Advantages: More scratch-resistance protection compared to acrylic, can be further enhanced by AR and generally looks more expensive.
Disadvantages: Not totally scratch-proof, harder to remove scratches and more expensive.
This is the best you can get. If you’re considering a timepiece that has sapphire crystal protecting the dial then you can rest assured you have the best kind of watch glass you can get at the moment.
You might’ve guessed, but it’s made from sapphire. Spoiler alert, but it’s a synthetic version rather than genuine. Sapphire is used for its incredible scratch-resistance and general durability. They look good, too. On the whole, you’d need a diamond to make a mark on it.
You might be thinking to yourself that you were certain that sapphires were blue. You’re not wrong. They are. They might also be purple, green, yellow or red, did you know that?
The colour is dependent on the presence of impurities like titanium (another surprise), iron, copper or chromium. These, and other materials, cause a hue. If you come across a genuine sapphire and it’s clear, you’ve got something rare there. This is why it’s easier to produce a synthetic version.
It was created by a chemist in France. He made huge sheets of the stuff by getting his hands on aluminium oxide and blasting it with heat and pressure. The powder turned into crystals, did some more magic to remove internal stresses so it’s strong as it can be. This is then pressed into a sheet and there you have sapphire crystal glass ready to be cut for watches.
It might be incredibly scratch-resistant but be aware it’s not invincible; it could still crack or shatter given a hard enough impact.
Advantages: Best scratch-resistant material on offer currently, and looks great.
Disadvantages: It’s very expensive and could still potentially shatter.
Hopefully you found that a worthwhile lesson. Why not continue your education and read our article on the types of watch you can buy?