Sapphire crystal vs mineral glass – what's the difference and which is best?
We compare sapphire glass and mineral glass directly – scratch resistance, shock resistance, price, and how they feel in light – so you know exactly what you're getting before choosing the glass type for your next watch.
Short answer
Sapphire crystal is harder and significantly more scratch-resistant than mineral glass, but it costs more. Mineral glass can give way upon certain impacts instead of shattering and is cheaper to replace. If you want crystal that stays scratch-free year after year, choose sapphire crystal – if you are looking for an affordable watch that is easy to service, mineral glass is more than enough.
Innehåll · 10 avsnitt
- Sapphire crystal vs mineral glass – quick comparison
- What is sapphire crystal?
- What is mineral glass?
- What is acrylic glass (Plexiglas)?
- Which crystal withstands the most?
- Can sapphire crystal crack?
- How do I know what crystal my watch has?
- Does the crystal affect the watch's price?
- Which crystal should you choose?
- Find a watch with the right crystal at Kronura
Sapphire crystal vs mineral glass – quick comparison
The most important difference is scratch resistance versus price, but the crystal is only one part of the watch's materials and construction. The table summarizes how the two most common watch crystals compare, so we will elaborate on each point below.
| Feature | Sapphire crystal | Mineral glass |
|---|---|---|
| Scratch resistance | Very high – stays scratch-free with daily use | Lower – scratched by keys, jewelry and hard surfaces |
| Hardness (Mohs) | Around 9, second only to diamond | Around 5 |
| Impact resistance | Resistant to scratches but can shatter upon a hard impact | Can give way instead of shattering |
| Reflection | Often anti-reflective treated – clearer dial | Rarely anti-reflective treated |
| Price and replacement | More expensive, and more expensive to replace | Affordable, cheap and easy to replace |
| Suitable for | Daily use, if you want it to stay scratch-free for a long time | Affordable everyday watch |
What is sapphire crystal?
Sapphire crystal is a synthetically produced sapphire material used as watch crystal. The material is grown in a lab, which provides uniform quality without the defects of natural stone. It ranks very high on the Mohs hardness scale – around 9, second only to diamond – which makes it extremely scratch-resistant. In practice, the crystal is not scratched by common objects such as keys, coins or tabletops; it essentially requires something as hard as sapphire or diamond to leave marks, and the crystal therefore stays clear and scratch-free even after several years of daily use. Sapphire crystal is often anti-reflective treated, which gives a clearer dial in bright light and reduces distracting reflections. Therefore, it is common in watches in a higher price class, where long durability and a sense of quality carry significant weight.
What is mineral glass?
Mineral glass is a hardened glass that withstands quite a lot in everyday life and has long been the standard on affordable watches. Through heat hardening, the glass becomes more durable than ordinary window glass, but the hardness is still around 5 on the Mohs scale – lower than sapphire crystal. This means that mineral glass is more easily scratched by keys, jewelry and hard surfaces. The advantage is the price and that the glass is easy and cheap to replace if it should be damaged. If the glass gets a superficial scratch, a watchmaker can also sometimes sand or polish it away, which is rarely possible with sapphire crystal. For many everyday watches, mineral glass is a perfectly good and forgiving choice, especially if the watch is not exposed to heavy daily wear.
What is acrylic glass (Plexiglas)?
Acrylic glass, sometimes called Plexiglas, is a plastic crystal found on vintage-inspired and budget-friendly watches. It scratches easily, but a major advantage is that superficial scratches can often be polished away, and that the material withstands impacts well without shattering. Since acrylic glass is soft and light, it is also shock-absorbing, which historically made it popular on older sports and pilot watches. Acrylic glass is a third alternative alongside sapphire and mineral glass, and suits you who like a softer, retro look at a low price.
Which crystal withstands the most?
It depends on what kind of stress you mean. Against scratches, sapphire crystal clearly wins – it is one of the hardest materials you can have on a watch and withstands daily wear without losing its luster. Against hard impacts, the picture is more nuanced: very hard materials are scratch-resistant but can be more brittle, while hardened mineral glass can give way slightly instead of shattering. For most who primarily want to avoid scratches in everyday life, sapphire crystal is the more wear-resistant choice over time.
Can sapphire crystal crack?
Yes. No watch crystal is indestructible. Sapphire crystal is very scratch-resistant, but a hard impact against an edge or a fall onto a stone floor can cause even sapphire crystal to crack. The difference compared to mineral glass is that in normal use you rarely get scratches on sapphire crystal, while a broken crystal is usually due to a heavy impact rather than normal wear. If you are going to use the watch heavily – at the gym, work or outdoors – it is primarily impacts you need to protect it against, regardless of crystal type.
How do I know what crystal my watch has?
The easiest way is to read the watch's specifications, where the crystal type is almost always stated as sapphire crystal, mineral glass or acrylic glass. At Kronura, the crystal type is listed in the product information for every watch. A common trick is also to look at how the crystal reflects light: anti-reflective treated sapphire crystal often gives a slight blue or purple tint at certain angles. If you are unsure, the specification is always the safest source.
Does the crystal affect the watch's price?
Yes, the crystal type is one of several factors that are reflected in the price. Sapphire crystal costs more to manufacture and process than mineral glass, and anti-reflective treatment adds even more. Therefore, you will most often find sapphire crystal in watches in a higher price class, while mineral glass keeps down the price on everyday models. At the same time, the movement, case material and brand determine at least as much – the crystal alone rarely explains the entire price difference between two watches.
Which crystal should you choose?
The choice depends on how you use the watch and what you want to spend. Two simple guidelines:
Choose sapphire crystal if …
You wear the watch daily and want it to look new year after year, or want a premium feel and a clearer, anti-reflective treated dial. Sapphire crystal is standard in the higher price classes.
Choose mineral glass if …
You want an affordable everyday watch and a crystal that is cheap and easy to replace if it is damaged. Mineral glass is more than enough when the watch is not exposed to heavy daily wear.
If you use the watch heavily – at the gym, work or outdoors – you should consider impact and water resistance (ATM) at least as much as the crystal, especially for sports and diving watches. If you like a vintage look, acrylic glass is an affordable alternative that can also be polished.
Casio
Edifice EFR-S108DE-2AVUEF
€144,95
Se klockan
Find a watch with the right crystal at Kronura
When you know what crystal type you want, it becomes easier to choose a watch. If you are looking for models where sapphire crystal is common, you can look among watches in a higher price class, or explore quality brands such as Citizen Super Titanium, Bering and Hamilton. The crystal type is always in the product information. Browse further among our men's watches and women's watches to find a model that suits your style and budget.
Featured watches
Watches with sapphire crystal
Citizen Super Titanium, Bering and Hamilton are mentioned above. All four have sapphire crystal.
Casio Edifice EFB-108D-1AVUEF
45 mm · 8 mm tjock
Bering Classic Ø34mm 14134-010
34 mm · 6 mm tjock
Citizen Super Titanium AW1240-57L
42 mm · 10 mm tjock
Hamilton Khaki Field King H64455533
40 mm · 11 mm tjock
- ✓ 2 års garanti
- ✓ Äkta märkesklockor
- ✓ 30 dagars öppet köp
- ✓ Fri frakt
- ✓ 4,6/5 på Trustpilot
Is sapphire crystal worth the higher cost?
For those who wear the watch daily and want to avoid scratches, sapphire crystal is often worth it, because the watch stays scratch-free longer. For a watch you use more rarely, mineral glass may be enough.
Can scratches be polished out of mineral glass?
Lighter scratches on mineral glass can sometimes be sanded or polished out by a watchmaker. Deep scratches are harder to remove, and then a crystal replacement is often easier because mineral glass is cheap to replace.
Does sapphire crystal crack easily?
No, not in normal use. Sapphire crystal is very scratch-resistant, but a hard impact against a hard surface can cause it to crack. Damage is usually due to impacts, not normal wear.
What is the difference between sapphire crystal and acrylic glass?
Sapphire crystal is hard and very scratch-resistant but more expensive. Acrylic glass is a plastic crystal that scratches easily but withstands impacts and can be polished, and is used primarily on vintage-inspired and affordable watches.
Which crystal is best for a sports watch or diving watch?
Sapphire crystal is popular on sports and diving watches thanks to its scratch resistance. Just as important is that the watch has the right water resistance for the activity, so consider both the crystal and the ATM rating.
How do I know what crystal a watch has?
The crystal type is stated in the watch's specifications – at Kronura, it is listed in the product information for every model. It is the safest source if you are unsure.