Watch Crystals — Sapphire, Mineral & Acrylic

The transparent shield protecting your dial.

💎 SAPPHIRE CRYSTAL

• Hardness: 9/10 Mohs (only diamond is harder)
• Virtually scratch-proof
• Used in nearly all modern luxury watches

🔲 MINERAL GLASS

• Hardness: 5-6/10 Mohs
• Cheaper, more scratch-prone
• Used in mid-range watches

🔵 ACRYLIC (HESALITE)

• Scratches easily BUT can be polished out with toothpaste!
• Doesn't shatter — it flexes
• NASA chose hesalite for the Moonwatch because sapphire can shatter in vacuum

📝 PRO TIP: The "water drop test" — on sapphire, a water droplet holds its shape as a tight bead. On mineral/acrylic, it spreads flat.