Copper, silver, or gold MC cartridge coils?

Dear @don_c55 :  Everything is important in the cartridge quality performance and certainly the kind of wire in the coils it's but not so important to define the cartridge signature because all depends of the whole cartridge design and in particular the cartridge motor where the coils are part of it and let me to tell you that even the coil wiring shape could be even more important that the coil type.

A cartridge designer design his cartridge to a very specific quality performance level characteristics and it's through the rigth and precise combination of each cartridge part and quality level build excecution of that design as he will achieve those targets/characteristics targets.

In the other side each cartridge is designed with a market price point in mind.

What kind of value can has for you if I tell you that silver wire is the best or if other gentleman tells you that cooper is the one to go?, for me has no value at all because what are you or we evaluating behind that kind of coil wire?: just nothing at all.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

One is preferable over the other two, IMO, as chosen by the designer and user.

Not all cartridge brands give you a choice.

I was thinking of ZYX brand.

Has anyone tried all three types in one brand. And which did you prefer and what were the perceived sonic differences?

Just looking for opinions. Everything in art and audio is subjective.

To Add to the list of Coil Wires being used.
Aucurum Wire,
( Gold Plated Six 9's Copper) known to be used by 
Ortofon for approx' 20 Years in some of their designs.

Koetsu Urushi,
( have a model that has a Silver Clad ' not plated'  Six 9's Copper )

I have been impressed with Ortofon Cartridges that have coils wound  Aucurum , as a result I now own a Cadenza Black, that I intend on having rebuilt to a change of Specification.

There are also Cartridge Tag Wire Pins used of different Metals, 
I am sure the combination of Coil Metals and Pin Metal will also have an
Sonic Signature.   
   

Since you asked for ZYX:

 I can say that tried both Silver Coil (Airy 3) and copper (Premium 4D) I think the last one (copper) is better, you can’t go wrong with copper coil from ZYX. 

Silver is definitely not warmer.