Copper, silver, or gold MC cartridge coils?

I wonder why nobody plays around with the wiring of MM or MI cartridges. Higher voltage maybe wire has less effect?

They do actually, LC-OFC versus PC-OCC.
Grace and Audio-Technica made different versions.   

Dear @edgewear : Yes you are rigth because Lyra asked for the Parnassus sample to build the Olympos and yes too with the Koetsu that does not needs a donor cartridge.

Yes, different application sonic benefits.

R.

Dear @mijostyn : I think that the more expensive high output ( MM/MI ) cartridges are the ones coming from SoundSmith and PL never says he is using silver or gold wire in the coils but cooper.

No singler vintage HO MM/MI use silver wire in its coils. The rule is cooper as with LOMC ones too .

Some LOMC , maybe by marketing issue, use silver or gold wire but this is not " normal " and perhaps only a marketing hype to ask higher prices for it. Only the manufacturers can tell us the true behind their choosed coils wire types.
R.

I have a Koetsu Jade Platinum cartridge which sounds amazing.  I understand it is the wiring and not the magnet that is platinum.   It is utterly natural-sounding, clear and seductive - can transport you into places no other source has achieved for me. 

can somebody clarify if there are indeed cartridges wound with platinum coils?  Some of the Koetsu's have platinum cobalt magnets and VDH does make a platinum IC but I have yet to see confirmation of platinum wound MC coils.