Element of one from Latvia according to one from Estonia? (6)

I believe the answer is:

cobalt

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'element' is the definition.
(cobalt is a kind of element)

I don't understand the rest of the clue.

(Other definitions for cobalt that I've seen before include "Magnetic-alloy element; a blue" , "Metal giving its name to type of deep blue" , "Metallic element, Co" , "Deep blue pigment" , "Sort of blue" .)

I've seen this clue in The Telegraph.

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