Every watch spec sheet lists a case material, a movement, a strap — and one line that gets skimmed past more than any other: the crystal. That’s a mistake. The crystal is the part of the watch you touch with your eyes every single time you check the time, and it’s the part most likely to get scuffed by a car key, a doorframe, or a rough day at work. What it’s made of matters more than most buyers realize, and the marketing around it is often deliberately confusing.
There are three materials in circulation: acrylic (also called hesalite or plexiglass), mineral glass, and sapphire crystal. Each one trades off scratch resistance, shatter resistance, and cost differently, and none of them is “the best” in every situation. Here’s what each one actually does, and why the right choice depends entirely on what you paid for the watch.
Acrylic: the old-school survivor
Acrylic is a molded plastic, the material NASA chose for the Omega Speedmaster that went to the moon — not because it was cutting-edge, but because it doesn’t shatter into sharp fragments under impact. That’s still its core advantage today: acrylic flexes and dents rather than cracking, which made it the standard choice on field and dive watches for decades.
The downside is obvious the first time you set your keys down on top of your watch — acrylic scratches if you look at it wrong. The upside is that those scratches buff out with a bit of toothpaste or a plastic polish, so a watch in service for forty years can still look presentable with occasional care. That’s part of why vintage collectors seek out acrylic crystals — they’re a feature of the era, not a flaw. On a new watch today, though, acrylic mostly shows up on budget fashion pieces where cost-cutting is the real reason it’s there, not heritage.
Mineral glass: the sensible middle ground
Mineral glass is ordinary glass that’s been chemically or thermally treated — tempered — to be considerably harder and more impact-resistant than the glass in a window or a drinking cup. It sits in the middle of the durability spectrum on every axis: harder than acrylic so it scratches less easily, but not as hard as sapphire; more prone to shattering than acrylic under a sharp impact, but far less prone to it than sapphire, which can crack from a fall onto a hard tile floor in exactly the situation a mineral crystal would survive.
This is the crystal on the overwhelming majority of watches priced under roughly €300, and there’s a good reason for that: it delivers real, everyday durability without pricing the watch out of reach. It picks up fine surface scratches with wear, the same way any glass does, but it shrugs off the kind of daily contact — a bag zipper, a table edge, a handshake — that would leave acrylic looking like sandpaper.
The Al Awaal uses mineral glass, and we’re not going to dress that up as anything other than what it is. At €110, mineral glass isn’t a corner we cut — it’s the correct engineering choice for a 41mm quartz watch at this price point, and pairing it with the true Eastern Arabic ٠–٩ numerals and 3 ATM water resistance gives you a watch built to be worn, not babied. If a watch at this price tells you it has sapphire, read the next section before you believe it.
Sapphire crystal: the premium option, with a real trade-off
Sapphire crystal is synthetic corundum, grown in a lab and cut to shape. On the Mohs hardness scale it sits at 9, just below diamond, which means almost nothing you encounter daily — keys, sand, a stone countertop — will scratch it. That scratch resistance is real and it’s why sapphire commands a premium: it can look new after a decade of wear in a way mineral glass won’t.
The trade-off is toughness, not hardness. Hardness and toughness aren’t the same property — a material can resist scratching brilliantly and still be more brittle under a sharp, concentrated impact. Sapphire is more prone to cracking or chipping from a hard knock than mineral glass is, which is why you’ll rarely see it on rugged tool watches, and why a cracked sapphire crystal is a genuinely expensive repair — often more than a modest watch itself costs, since replacement requires precision-cut sapphire and specialist fitting.
Sapphire earns its keep on watches in the €500-and-up range, where the crystal cost is a smaller fraction of the total price and the owner is paying for a piece meant to stay pristine for a lifetime. Below that, you’re often paying a premium that doesn’t match the rest of the watch’s build.
The “sapphire-coated” trap
Watch out for wording like “sapphire-coated mineral glass” or “sapphire-treated crystal.” This is mineral glass with a thin sapphire-like coating on the surface — and that coating wears through with normal use, at which point the crystal scratches like uncoated mineral glass underneath, sometimes worse if the coating flakes unevenly. It’s a genuine material with a genuine, small benefit, but it is not sapphire crystal, and pricing it like sapphire is where the marketing turns dishonest. If a listing doesn’t say “sapphire crystal” without qualifiers, assume it isn’t one.
Mineral, sapphire, and acrylic side by side
| Crystal | Scratch resistance | Shatter resistance | Typical price range | Repair cost if damaged |
|---|---|---|---|---|
| Acrylic | Low — scratches easily | Very high — flexes, doesn’t shatter | Under €100, or vintage watches | Low; often DIY-polishable |
| Mineral glass | Moderate — resists daily wear well | Good — tempered, absorbs shock | €80–€300 | Low to moderate |
| Sapphire crystal | Very high — near scratch-proof | Moderate — can crack under sharp impact | €400 and up | High; specialist replacement |
Caring for a mineral glass crystal
Mineral glass rewards a little basic care. A few habits keep it looking sharp for years:
- Wipe it with a soft microfiber cloth rather than your sleeve or a paper towel, which can grind grit into the surface.
- Avoid setting the watch face-down on rough surfaces like stone countertops or unfinished wood.
- Fine hairline scratches can often be reduced with a dedicated plastic/glass polish and a soft cloth — test on a small area first.
- Rinse off salt water, sunscreen, and sweat after wear; residue left to dry can dull the surface over time.
None of this is watch-collector fussiness — it’s the same basic care you’d give a pair of sunglasses, and it’s enough to keep mineral glass looking clean well past the watch’s first year.
So what should you actually buy?
Match the crystal to how the watch will be used and what it costs. A vintage-styled piece under €100 with acrylic is honest about what it is, and part of the charm is that you can polish out scratches yourself. A watch in the €80–300 range with mineral glass is the sensible default for daily wear — it’s tough enough for real life without the fragility or repair bill of sapphire. A watch north of €500 is where sapphire starts to justify its cost, because the rest of the build usually matches that level of investment.
What should raise a flag is a watch priced like the first category claiming the durability of the third. We wrote a broader breakdown of what “reasonable specs” actually look like at this price point in our guide to choosing a great watch under €150 — the short version is that honest spec sheets tend to have unglamorous words like “mineral glass” and “alloy case” on them, not superlatives.
The crystal is also only one part of how a watch holds up day to day — water resistance rating matters just as much for anyone who wears a watch in the shower, rain, or while washing their hands. We’ve covered what the ratings actually mean, and don’t mean, in our explainer on what 3 ATM water resistance means.
Frequently asked questions
Is mineral glass good, or is it a downgrade from sapphire?
Mineral glass is good — it’s not a downgrade, it’s a different tool for a different job. It offers solid scratch resistance for daily wear and better shatter resistance than sapphire, at a fraction of the cost. Calling it inferior only makes sense if you ignore the price and durability trade-offs sapphire brings with it.
Can mineral glass be polished if it gets scratched?
Yes, to a point. Fine surface scratches often respond well to a dedicated glass or plastic polish applied with a soft cloth. Deeper scratches or scuffs may reduce but not fully disappear. It’s less forgiving than acrylic, which polishes out almost completely, but far more repairable than a scratched sapphire crystal, which generally can’t be polished at all without professional resurfacing.
Why don’t more budget watches just use sapphire if it’s better?
Because sapphire isn’t better in every way — it’s harder but more brittle, and it costs significantly more to produce and fit. Putting a genuine sapphire crystal on a €100–150 watch usually means cutting quality somewhere else, in the movement, case, or strap, to cover the cost. Brands that advertise sapphire at that price point are frequently using a thin sapphire coating over mineral glass, which is a different, lesser thing.
Does the Al Awaal use sapphire or mineral glass?
The Al Awaal uses mineral glass. At €110, that’s the appropriate crystal for the price and build — tempered for real scratch and impact resistance, without the fragility or repair costs that come with sapphire. It’s paired with a 41mm alloy case, 3 ATM water resistance, and true Eastern Arabic ٠–٩ numerals on the dial.