@all Thank you for your input 
It was sold to me as byzantine broad axe , modern cleaned and conserved, to me. So evgeny was spot on with his excavated example which looks very similar.  
Its from a london collection which contained a lot of viking axeheads formed in the 1950s. 
 
I have attached more pictures of the axehead. It seems as there is some black coating and then some kind of wax applied on top of it.
		 
		
		
		
			
		
		
		
		
		
		
		
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