What is the silver?

[smurfchops]

I have some every-day cutlery which is a grey tinny colour, and some more expensive cutlery that has a nice yellowy type of colour as they have aged. I have knives and forks but need dessert spoons, I am looking on eBay but need to know what type of silver they are. Would they be called Sheffield ?? They are not solid silver, but have that expensive chunky 'look' .