Greater Glyph of Warding

This spell functions like glyph of warding, except that a greater blast glyph deals up to 10d8 points of damage, and a greater spell glyph can store a spell of 6th level or lower.

Read magic allows you to identify a greater glyph of warding with a DC 16 Spellcraft check.

Material Component: You trace the glyph with incense, which must first be sprinkled with powdered diamond worth at least 400 gp.