What is a Hardlex Crystal on my watch? Pros & Cons?

Question

I Have A Seiko watch with this Crystal on the face. Want to know is it scratch proof or shatter proof.

Answer 1

Hardlex is a Seiko proprietary type of hardened mineral crystal and comes in at least two different varieties (what goes in Seiko 5's is not the same quality of what goes into ISO divers). Hardlex is closer to 7 in the Moh's scale, but is much more flexible than sapphire. IOW's sapphire is harder but more brittle. Hardlex will scratch easier but resists impact much better.

Answer 2

You won't find any what crystal that will be scratch proof.  They do state that the hardlex crystal is scratch resistant.  The crystal is much stronger than they use to be.

Seiko employs a variety of crystals for its watches, ranging from acrylic crystals on lower priced watches, to {Hardlex/Mineral, a crystal constructed of silicon and barium and heated to create hardness to withstand scratches and marring.} From time to time Seiko also uses Sapphlex, a glass crystal protected with a sapphire coating to be scratch resistant or sapphire crystal.