Can you identify the spigot attached to this water heater?
It's called nickel brass, white brass or nickel-plated brass. It's perfectly acceptable. The bigger issue in the picture is the copper fitting attached to the tank, it should be a barstock or brass FIP. A bar stock or brass fitting or dielectric union should be put in between any black iron and copper fittings. The tee looks a little odd. But if it's brass it should be fine. 

Not exactly the same I'm sure, but similar. 


http://www.jomarvalve.com/products/categories/boilerdrains/brass.html