Gold SIMM on tin socket?

[Acill]

It should be fine as long as its actually gold plate. Some metals dont react together well. Gold is a great conductor and doesnt react with other metals like aluminum and steel do for example. The problem you could face is called bi-metallic corrosion.

In this case, its safe though. Here is a good explanation of it. http://www.jsbtech.com/download/Effects%20of%20Galvanic%20Corrosion%20on%20Au-Sn-Plated%20Contacts.pdf