Hi, I have acquired an interesting fossilized stone and am not sure if it is healthy to put in a tank.  It has sat on the sideboard of someone who smoked a great deal.  I have put it in very hot water and scrubbed it and lot of air bubbles are coming out.  I would like to start a tank but would this stone be suitable for a fishtank or is it contaminated by the smoke? Any answers much appreciated.  Many thanks.
		
		
	
	
		
	
				
			
	
	            
			