Antique rings can either be family heirlooms passed on from one generation to the next, or something that you seek out at a junk shop or an antiques dealer.
If there is a certain style of ring you're a going for that is more classic by design then it is certainly worth having a look at antique rings as you are quite likely to get something more unique, with a little bit of history attached to it.
If you have a particularly special ring that has been passed through the family this may be a great sentimental gift to give your wife as an eternity ring when the time is right.
 Rings given for eternity are usually gifted upon the birth of the first child or when you reach a significant milestone anniversary.
There are several main types of eternity rings and you may well find an antique ring that is the style you are after, especially if you go for a classic rather than contemporary design.
  The main types are a full, half or tri-diamond arrangement.
With a full arrangement the gem stones, usually diamonds, are situated all the way round the ring.
A half arrangement will have diamonds covering one half of the circumference of the ring, and this will be the upper most side when it is worn.
The final traditional design is a tri-diamond arrangement, which will usually be three larger diamonds next to each other.
Obviously there are other variations of the above but these are the main types of eternity ring you will find, especially when looking for an antique one.