Ruby-Quartz

From Marvel Database

The only known natural substance that block the optic blasts of Cyclops without damage. The crystal resonates at the same frequency as the psionic field that protects both Cyclops and Havok from their own powers.

Used in:

• The android double of Cameron Hodge was encased in crystal armor that resembled a prism. The faceted armor could reflect the optic blasts of Cyclops.
• Cyclops' visor.
• Cyclops' eye glasses.
• Shades worn by both Rogue and Mimic.
• In the Age of Apocalypse, Cyclops wears a ruby-quartz visored monocle over his right eye.

First Appearance: Uncanny X-Men Vol. 1 #1