Guide
Sapphire vs Mineral Crystal
Why every modern enthusiast watch uses sapphire — and what the trade-offs really are.
Quick answer: Sapphire crystal (9 on the Mohs scale) resists everyday scratches far better than mineral glass (5–6) or acrylic (about 3). Mineral is cheaper and less brittle; acrylic is soft but polishes out. Every Rose & Rotors watch uses sapphire.
Shop Luxury Homage Watches →Hardness compared
- Sapphire: 9 Mohs — only diamond scratches it reliably
- Mineral glass: 5–6 Mohs — scratched by sand, concrete and steel
- Acrylic: about 3 Mohs — scratches easily but polishes out
Trade-offs
Sapphire can chip under a sharp direct impact and reflects more light unless anti-reflective coated. Mineral is a little tougher against impact. Acrylic hardly ever shatters, which is why vintage watches used it.
How to tell which you have
Put a drop of water on the crystal: on sapphire it beads tightly, on mineral it spreads out. Sapphire also feels colder to the touch.
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Frequently Asked Questions
Can sapphire crystal break?
Yes, under a hard direct impact on an edge, but it won't scratch in normal wear.
Is mineral glass bad?
No, but it scratches more easily over time.
Do all Rose & Rotors watches have sapphire?
Yes, as standard.