According to Ki Empu Djeno Harumbrodjo:
http://www.joglosemar.co.id/whos/djeno.html
“Physically, the materials for manufacturing must be prepared such as, 12 Kg of Iron; 0.5 Kg of Nickel, 100 grams of meteorite”
This means that a typical meteorite pamor keris consists of 95% Iron, 4% Nickel and only 1% meteorite material.
It would indeed be impossible to detect that 1% meteorite content without chemical analysis.
I’m guessing that he adds the extra nickel to obtain a bright pamor as the meteorite if used without adding nickel would probably produce a dull pamor.