I've often wondered why silver plating doesn't replace gold entirely in smaller electrical connectors. Perhaps dendrite growth becomes a concern, or perhaps because it just looks dirty over time and consumers would question it. *Scrapper tip: Some people are wise to this and if they have access to retired equipment, will disassemble these to harvest the little chunks of silver. The contacts themselves are often solid, not plated, as they are subject to erosion as part of normal use. However, tinkerers like me will often find more value in the smaller relays if kept as they are.