Glyph of Concentration

Acquisition
Skill trainers Signet of Capture
 * Steig (Camp Rankor)
 * Dakk (Ember Light Camp)
 * Ice Drake (Borlis Pass)
 * Whiskar Featherstorm (Griffon's Mouth)

Trivia

 * This glyph may have once been known as "Glyph of Gesture", see GameSpot preview of the Elementalist.