Phone durability videos often scratch screens with picks labelled 1 to 10 and declare: "scratches at level 6, with deeper grooves at level 7." What does that actually mean, and why can't manufacturers make screens that never scratch?
The Mohs hardness scale
The Mohs scale ranks minerals by which can scratch which, from 1 (talc) to 10 (diamond):
| Mohs level | Example |
|---|---|
| 2–3 | Fingernail, copper coin |
| 4–5 | Steel knife (~5.5) |
| 6 | Feldspar (and many glass surfaces) |
| 7 | Quartz (sand, dust) |
| 8 | Topaz |
| 9 | Sapphire |
| 10 | Diamond |
It's ordinal, not linear: the jump from 9 to 10 is enormous compared with 6 to 7.
What phone scratch tests show
Most phone cover glass (Gorilla Glass, Ceramic Shield, etc.) shows scratches starting at level 6, with deeper grooves at level 7. That means:
- Keys, coins and knives (below 6) generally won't scratch it.
- Quartz sand (7), common in pockets and dust, can.
That's why screens accumulate micro-scratches from pockets and bags.
Why not use sapphire?
Sapphire (Mohs 9) is extremely scratch-resistant, but:
- More brittle: it's more likely to shatter when dropped.
- Expensive and heavier.
- More reflective.
Glass makers balance hardness (scratch resistance) with toughness (resistance to cracking). Phones drop far more often than they meet diamonds, so drop resistance is often prioritised.
Photo by Sergey Meshkov on Pexels
Limitations of pick tests
- Mohs picks are inconsistent in force and technique.
- Real-world scratches come from particles under pressure, not single picks.
- Coatings (anti-reflective, oleophobic) can wear differently from the glass underneath.
Practical takeaways
- Use a tempered glass protector. Replacing it is cheaper than replacing the screen.
- Keep phones out of pockets with sand or grit.
- Clean screens gently; don't wipe gritty dust across them.
- Newer glass-ceramics (e.g., Gorilla Glass Armor) improve scratch resistance, but no phone glass is scratch-proof.
Video explanation
Summary
Most phone glass scratches at Mohs level 6–7, the hardness of common sand. Manufacturers trade some scratch resistance for drop toughness, so a screen protector and clean pockets remain the best defence.
Compare phones with the latest protective glass on infozme's top-rated phones.
Cover photo by RDNE Stock project on Pexels. This article was written with the help of AI.
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