Stormphrax

In rare cases, great storms from the elemental plane of air have been known to cross into the prime material. When a bolt of lightning is released from one of these raging maelstroms, it crystallizes upon impact with the ground to form a jagged spire of glimmering Stormphrax.
Stormphrax is a crystal of concentrated lightning, elemental power incarnate. It takes the appearance of a pure, light blue crystal with bright tendrils of electrical power coursing below the surface.
• When a fragment of stormphrax is snapped or destroyed, it annihilates and deals 3d10 lightning damage to each creature within 10 feet of it. Even when stable, sparks jump to it from metallic surfaces within 10 feet of it, and it constantly emits an audible buzzing sound.
• Weapons made of stormphrax deal lightning damage rather than their regular type, and a creature hit by one can't take reactions until the beginning of its next turn due to the natural property of stormphrax.
• Creatures wearing armor made of stormphrax have resistance to lightning damage. (Striking a creature wearing stormphrax armor doesn't provoke the shocking natural property.)