What is Vermeil?
First, let's talk about how you pronounce "vermeil." vur-MAY, yep, it's French. You may also hear vermeil called "gilt silver" or "gilded silver."
Now let's get down to what this stuff is! I covered gold plating and gold fill in another blog post. If you haven't read it, or need a refresher, read that first. Don't worry, it's brief and there are pictures to make it fun.
The other differences between the two is that the plating on vermeil must be a minimum of 2.5 microns thick, and the gold has to be 10 karats or more. In gold plating, the gold thickness will vary and can be miniscule. The result is that the plating is worn through rather quickly. You'll be able to see the metal that is under that plating. When the piece of jewelry is in contact with your skin, necklaces are a great example for this, your skin may react and leave your skin discolored. Remember that the base metal is copper, brass, or some alloy and many people have allergic reaction to those metals.
To be fair, the plating for vermeil can wear away, but the thicker layer of 10k (or higher) gold will take quite a while to wear away. There can be cracking of the gold layer. This occurs if the sterling silver base was not properly prepared for the plating phase of production. It can also crack if the piece is dinged or bent. The upside is that the metal beneath vermeil pieces is sterling silver and will probably not cause any skin discoloration, and you're not likely to have an allergic reaction to the sterling silver.
I write these sorts of posts to give you information so that you can make the choice that's best for you when selecting jewelry for yourself or others. I see a lot of misleading descriptions of jewelry out there. Often, I think it's not meant to deceive. The jewelry maker puts "gold" on the description and the consumer may or may not know that they mean gold fill or gold plated. If a ring is $50, it probably isn't gold, it's likely plated. Nothing wrong with this if that's what you want, but I want you to know what you're buying.
For more fun and informative gold and plating facts, read these:
What is Gold-Filled Wire?
Gold Demystified: Part 1
Gold Demystified: Part 2