** Salsa dancer emoji means that though your brass will change color, it's just tarnish, and can probably be cleaned with salsa. Ketchup works better - it's the acid in the vinegar and tomatoes that cleans off the tarnish!
Moral of the story : if it seems too good to be true . . . it probably is. Gold is at $1,095.33 per ounce right now, and that's down from previous years. So if you see a necklace labeled "14k gold" or "gold" and it's under $100 dollars, it's likely gold plate, which will wear off and look gross. If it's from a larger company (say you see it on Bloomingdales or a site like that) and it's under $200 and described as "gold," again, it's probably not gold and is a plated counterpart. Gold filled jewelry is usually made by people with small or individually run companies, so they're more likely to specify gold filled. But if you come across a piece labeled as "gold filled' and it's under $25 dollars, you have every right to be suspicious.
Still unsure about what these terms mean? Here are some more blog posts to help you out :