Sapphire Crystal vs. Mineral Crystal

Crystal is the face of the watch. Yet, much less effort goes into selecting the right crystal and guys end up scratching or breaking their watch.

And believe me, you don’t feel the same thing with your watch after its glass is repaired.

Therefore, knowing you Watch Crystal before making the big purchase would be the smart move.

Sapphire and Mineral Glass are the Big Gs, in the watch crystal game.

Take help from this guide, if you want an in-depth Sapphire Crystal vs. Mineral Crystal comparison.

The Ins and Outs of Sapphire Glass

Don’t be confused by the term ‘Sapphire Glass.’ It’s a misnomer; sapphire isn’t glass at all.

In the context of watches, Sapphire Crystal is typically made from synthetic sapphire, a crystalline form of aluminum oxide.

It’s transparent, extremely hard, and second only to diamond in its hardness rating.

The manufacturing process of Sapphire glass creation is called Verneuil – or flame fusion – wherein aluminum oxide is melted and then resolidified to form a single crystal.

This crystal is then shaped and polished into the final crystal used in watches.

The exacting process takes months from crystal to slice.

And with the hardness, scratch resistance and good visibility make Sapphire glass an expensive or luxury option among watches.

Benefits of Sapphire Crystal

• Scratch resistance: Sapphire Crystal has a Mohs score of 9; second only to diamond in hardness, making it nearly scratch-proof.
• Impact resistance: Along with being hard, Sapphire glass also has a significant amount of flexibility and can withstand high-impact forces without breaking.
• Clarity: Sapphire glass provides excellent clarity for viewing the watch face. The special crystalline structure keeps the watch dial clear even after a year.
• Durability: Sapphire glass is highly durable and can last for many years without showing signs of wear or damage.
• Luxurious appearance: The hardness and scratch resistance of Sapphire Crystal make it an attractive choice for high-end or luxury watches, adding to their overall value and appeal.

What about Mineral Crystals?

Mineral crystal, as its name suggests, is made from silica (a type of mineral).

This type of glass undergoes a hardening process, making it more scratch-resistant than regular glass, but less so than sapphire.

Its Moh score is typically around 5, which means it sits in the middle of the hardness scale.

Benefits of Mineral Crystal

• Affordability: Mineral glass is significantly cheaper to produce than sapphire, making it a more budget-friendly option for watches.
• Resistance to Shattering: While less hard than sapphire, mineral glass is more likely to withstand impacts without shattering, making it a durable option.
• Ease of Production: The production process of mineral glass is less time-consuming and complex compared to sapphire, allowing for quicker manufacturing times.
• Clarity: Despite its lower price point, mineral glass still offers good clarity for viewing the watch face, ensuring functionality is not compromised.

Head to Head: Sapphire Crystal vs. Mineral Glass

Whether you’re getting your first watch, or getting an upgrade, knowing the ins and outs of these watch crystals will always help you.

It would also be very practical when buying second watches.

Here’s how Sapphire Crystal vs. Mineral Glass stack up

Look and Feel

When it comes to color, both sapphire and mineral glass are typically clear.

However, the base shade of sapphire is Milky Pink or True White. The Mineral glass, in comparison, has a bluish tone.

The thickness of the glass can vary depending on the presence of Anti-reflective (AR) coating.

Therefore, thickness alone is a somewhat raw factor.

Touch, however, is a distinguishing factor. Sapphire crystal feels colder to the touch glass due to its high thermal conductivity and it’s quite smooth.

Mineral glass is slightly warmer and does not have the same ultra-smooth texture, but it still feels solid and durable under the fingertip.

Hardness, Density, and Other Refractive Properties

Sapphire Crystal is the hardest watch crystal available, registering a 9 on the Moh’s scale.

In contrast, Mineral Glass sits at around 5-6, making it much less resistant to scratches.

The hardness of Sapphire practically makes it scratch-proof. Only another sapphire and diamond can scratch the sapphire glass.

Sapphire crystal is also safe from scratching from your typical screwdriver.

Some materials that can scratch sapphire as silicon carbide, tungsten carbide, and boron nitride, boron. But how often do you encounter these? Never!

However, sapphire is also more brittle. It means it is more likely to crack or shatter from hard impacts.

Mineral glass has a lower density, making it lighter and more scratch-prone than sapphire.

It’s also less brittle and can withstand greater impact forces without breaking.

Other things like luminosity and reflectivity are closely matched in both Sapphire and Mineral Glass.

Water Drop and Waterproofing

If you put a drop of water on sapphire, the water will stay as a drop.

While on mineral glass, the drop will spread.

It’s because sapphire is Hydrophobic and Mineral Glass is hydrophilic.

Concerning waterproofing Sapphire Crystal and Mineral Glass waterproof.

With appropriate gasket design and case construction, both types of watch glass can withstand pressure at varying depths.

It’s important to note that the glass type alone won’t determine the watch’s water resistance.

The case, crown, back cover, and in some cases, the pushers, all play significant roles in ensuring a watch maintains its waterproof properties.

I recommend reading this guide on waterproof vs. water-resistant watches to be more clear about this concept.

Sapphire Crystal vs. Mineral Crystal: Which One Should You Choose?

Choosing between sapphire crystal and mineral glass comes down to your aesthetic preferences and style priorities.

If you want a watch that is incredibly scratch-resistant and offers a luxurious look, then sapphire crystal is your best bet.

However, if you’re on a budget or prefer a slightly lighter watch, mineral glass can be a great option.

But don’t take Mineral glass as an all-bad option.

In many cases like G-shock, your primary requirement is resistance to impact rather than getting your watch scratched.

With less weight and more durability, Mineral glass might be an excellent choice for your watch in such scenarios.

My recommendation is, if it’s an everyday watch that you plan to wear for years, go with Sapphire Crystals.

With a sports watch for rugged use, Mineral Glass will serve you well.

I also recommend reading our other guides on Watch Crystals like Hardlex to be informed about every matter.