Acrylic vs Mineral vs Sapphire Watch Crystals: Pros, Cons, and Differences

The watch crystal is often overlooked, but it plays a far more important role than many people realise. It’s the transparent “glass” that protects the dial and hands, but it’s also a key structural component of the watch. A good crystal must balance clarity, durability, scratch resistance, and impact protection—all while complementing the watch’s design and purpose.

In this guide, we’ll break down the three main types of watch crystals used in modern watchmaking—acrylic (hesalite), mineral, and sapphire—and explain their benefits, drawbacks, and which one might be best for your lifestyle.

The Three Main Types of Watch Crystals

Modern watches typically use one of the following crystals:

1. Acrylic (also known as Hesalite or Plexiglass)

2. Mineral Crystal

3. Sapphire Crystal

Each material has its own strengths, weaknesses, and ideal use cases.

Watch Crystals Acrylic vs Mineral vs Sapphire

Acrylic (Hesalite) Crystal

Acrylic crystal is a transparent plastic that has been used in watchmaking for decades. It’s lightweight, affordable, and easy to shape, which allows watchmakers to create domed or curved crystals that add vintage charm and visual depth to a watch.

Although acrylic is softer than mineral or sapphire, that softness brings an important advantage: flexibility. Acrylic crystals are far less likely to shatter on impact. Instead of cracking, they tend to absorb shocks—making them surprisingly tough in real-world use.

In fact, acrylic crystals have an impressive pedigree. They’ve been to space on the Omega Speedmaster and to the summit of Mount Everest on Rolex watches—a testament to their reliability in extreme conditions.

Pros of Acrylic Crystal

• Lightweight and comfortable on the wrist

• Highly impact-resistant and unlikely to shatter

• Naturally non-reflective (no anti-reflective coating needed)

• Scratches can be polished out, often restoring the crystal to like-new condition

• Gives watches a warm, vintage aesthetic

Cons of Acrylic Crystal

• Scratches more easily than mineral or sapphire

• Less resistant to chemicals and solvents

• It can develop yellowing or haze over many years if poorly maintained

One major benefit of acrylic is that scratches are not permanent. Minor scuffs can often be polished out, although it’s best to leave this to a professional to avoid uneven surfaces or deforming the crystal.

Best for: Vintage-style watches, tool watches, military watches, and anyone who values impact resistance and classic aesthetics over scratch resistance.

Mineral Crystal

Mineral crystal is made from tempered silica glass and sits firmly between acrylic and sapphire in terms of performance and price. It’s harder and more scratch-resistant than acrylic, while still being relatively affordable to manufacture.

Because of this balance, mineral crystal is extremely common in modern watches, especially in the mid-range market. It offers good clarity and durability for everyday wear.

Some manufacturers enhance mineral crystals further by applying coatings. For example, Citizen uses sapphire-coated mineral crystal on many of their dive watches, improving scratch resistance without the full cost of sapphire.

Pros of Mineral Crystal

• More scratch-resistant than acrylic

• More affordable than sapphire

• Good clarity and durability for daily use

• Less brittle than sapphire

Cons of Mineral Crystal

• Can still scratch over time

• Scratches generally cannot be polished out

• More prone to shattering than acrylic under severe impact

Once a mineral crystal is scratched or cracked, replacement is usually the only option. However, it offers a strong balance of performance and value for most wearers.

Best for: Everyday watches, sports watches, and buyers who want durability without the higher cost of sapphire.

Sapphire Crystal

Despite the name, sapphire crystal is not glass. It’s made from synthetic sapphire, which is crystallised aluminium oxide. On the Mohs hardness scale, sapphire ranks at 9, just below diamonds at 10.

This extreme hardness makes sapphire crystal exceptionally scratch-resistant. In normal use, only very hard materials—like diamonds or certain industrial abrasives—can scratch it.

However, this hardness comes with trade-offs. Sapphire is more brittle than acrylic or mineral crystal, meaning it can crack or shatter under a sharp impact. It’s also significantly more expensive to produce, as it must be ground and shaped from solid blocks using specialised tools.

Pros of Sapphire Crystal

• Extremely scratch-resistant

• Maintains clarity for many years

• Premium look and feel

• Ideal for long-term ownership

Cons of Sapphire Crystal

• More expensive

• More brittle than acrylic or mineral

• Can shatter under sharp impacts

• Requires an anti-reflective coating to reduce glare

Best for: Luxury watches, dress watches, and anyone who prioritises scratch resistance and long-term clarity.

Which Watch Crystal Is Best for You?

There’s no single “best” watch crystal—only the best one for your needs.

• Choose acrylic if you value impact resistance, vintage charm, and easy maintenance.

• Choose a mineral if you want a solid all-rounder at a reasonable price.

• Choose sapphire if scratch resistance and long-term clarity matter most to you.

Each crystal type has earned its place in watchmaking history, and understanding their differences helps you choose a watch that truly fits your lifestyle.

Watch crystals Acrylic vs Mineral vs Sapphire?