K1 Mineral Glass is a super-hardened glass that is created by an innovative grinding process.  Crystal clear, K1 Glass is scratch and impact resistant, and is known for its strength and superb clarity, making it the ultimate glass for watch faces used by watchmakers.  According to the Vicker Hardness Test, Sapphire has a hardness of around 1900, K1 around 700 and Mineral Glass around 380.  For the Mohs Hardness Scale (from 0-10, the hardness of a diamond is 10): sapphire is around 9, K1 is around 6 and mineral glass is around 4.  For our useful guide for watches that offer this feature:


For more information about watch crystal –



The Davosa-USA.com website is NOT affiliated in any way with Audemars Piguet, Franck Muller USA, Inc. Richard Mille or Richemont Companies, Seiko, or any other brand which is not Davosa Swiss. Rolex is a registered trademark of Rolex USA. Davosa-USA website is not an authorized dealer, reseller, or distributor for Rolex and is in NO WAY affiliated with Rolex SA or Rolex USA or any other brand besides Davosa Swiss.
October 25, 2022 — Davosa Editor

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