An outright blessing, this element! (5)
I believe the answer is:
boron
'this element' is the definition.
(boron is a kind of element)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for boron that I've seen before include "component of steel" , "element needed for steel" , "Atomic no 5" , "Non-metallic element, symbol B" , "Metalloid element, B" .)