Not everything that shines is sapphire. Watch glasses: what no one tells you

Did you know that a watch crystal can say more about its purpose than about its price? Many people believe that “if it’s not sapphire, it’s not good.” But… what if I told you that some of the best watches in the world use other types of crystals for very specific reasons? Today we’re going to uncover a small mystery: understanding why different watch crystals exist and how each one is designed to suit your lifestyle. Stay with us, because by the end you’ll discover which crystal truly fits you.

Why is the crystal so important in watches?

The crystal is not just a “window” to tell the time. It’s a technical component that must withstand impacts, pressure, temperature changes, and—most importantly—real everyday use. That’s why there is no single “better” crystal, but rather crystals that perform better in different contexts. Brands you’ll find at Iguana, such as Citizen or G-SHOCK, choose their crystals based on each model’s function, not just on cost.

Types of watch crystals

1. Acrylic crystal: the most flexible and impact-resistant

Acrylic crystal (or hesalite) is lightweight, warm to the touch, and surprisingly impact-resistant. It scratches more easily, but it can also be polished in just a few minutes. That’s why it remains a fantastic option for vintage-inspired watches or models designed for heavy use. Perfect examples include classic lines such as the Zeppelin LZ120 Rome Lady or some Sinn models, like the Sinn 356 PILOT Classic .

2. Mineral crystal: the ideal balance for everyday use

Mineral crystal is the most common choice in modern watchmaking because it combines good scratch resistance with excellent impact durability. Brands like Aston Martin or Maserati use it in their collections. You’ll also find it in Vostok Europe watches—perfect for adventures and demanding environments. If you’re looking for a reliable all-round watch, mineral crystal is often your best ally.

3. Sapphire crystal: maximum hardness and elegance

Sapphire is the king of scratch resistance. It’s used in premium watches because it maintains flawless transparency for decades. High-end models such as the Sinn 556 , Ball Engineer Marvelight or the U-Boat Classico Sommerso incorporate sapphire to deliver a more luxurious and long-lasting experience. But—and here’s the key—sapphire can be more fragile when subjected to strong impacts. That’s why it’s not always the ideal choice for adventure watches or extreme sports.

Why don’t all watches use sapphire crystal?

Because each crystal serves a different purpose. A professional dive watch, such as the Citizen Promaster, needs a crystal that can withstand sudden pressure changes. An urban-style model, like G-SHOCK, prioritizes resistance to shocks and drops. A dress watch, such as the Herbelin Cap Camarat, focuses on clarity and the beauty of sapphire. It’s not about price—it’s engineering applied to real-world use.

How to choose the right crystal for your next watch

Think about yourself first—not the spec sheet. How do you live with your watch?

• Sport or adventure use: mineral or acrylic.
• Balanced everyday use: mineral or hardened acrylic (such as plexiglass).
• Elegance, office, or collecting: sapphire.
• Vintage aesthetics: acrylic.

When your lifestyle meets the right technology, a watch becomes a trusted companion… not a concern.

The conclusion you didn’t expect

There is no such thing as the “best crystal.” There is the perfect crystal for you. And that’s the beauty of watchmaking: every element—from the movement to the crystal—is designed to tell a different story. Whether it’s the brilliance of sapphire, the toughness of mineral glass, or the warmth of acrylic, each crystal has a purpose and a character worth understanding.

Have questions? Want a personalized recommendation? Contact us and we’ll be happy to help.