an jweller can resize the ring by expanding it or contrasting it.you can increase its size by heating it and can be made smaller by making it cold
If she has very small hands and fingers then buy her a size 5 (jewelers can cut the ring down two sizes if it's too big.) If her hands are fairly large or close to the size of your hand then you can get a size 8 or 9 and have the jeweler cut the ring to fit her. Be sure to keep your bill of sale from the jeweler you purchase the ring from. Another way is to go to the jewelry store and if you see a sales woman there look at her fingers and see if you can find a sales woman with the close to the same size of hands and fingers as your girlfriend.
There are many online tools that allow you to resize the images and download it easily. Here are the top 4 online tools:ResizeImagePicResizeSimpleImagereSizerImageResize
This would be available at any jeweler's supply store, search online for one near you, have you heard of google?
sizing handles
Drag the sizing handles, babe. ;D
You can usually make gold rings smaller, but making them larger requires an experienced jeweler.
In order to resize a ring you must go to a jeweler, preferably the one where you originally bought the ring (if you want to get a low price!). If the ring is a simple band that needs to be enlarged, usually the jeweler will use special tools in order to expand it. Another method used in resizing is heating, which makes the metal soft enough to stretch. In order to reduce the size of a ring, the piece of metal that's no longer needed is cut out of the ring before it's welded back together.
A local jeweler can answer your question when you show the jeweler the ring.
It depends
Generally class rings are purchased through an application that one normally would receive from booths located in their school. So if you purchased a ring which isn't the correct size then, I would highly recommend you purchase one online if they have a website or you could simply take the ring to a jeweler and have them re-size it.
Whether or not a ring comes with a Certificate of Authenticity depends on the policy of the jeweler selling the ring. However, if you want a certificate of value for your ring, it is easy to take it to a jeweler and have it assayed.
any jeweler
You take your ring to a local jeweler and ask that the jeweler test the diamonds with a probe to confirm that they are, or are not, diamonds.
The jeweler has ring measurements. You just try on the different ring sizes.
The initials of the goldsmith/jeweler who made your ring.
In theory you can size a simple gold band down to almost any real size. Some rings have stones, designs or certain types of setting work that makes it so that it can't be sized so much or even not at all. That depends on the ring design, and a good jeweler can tell you that, and why.
Take it to them and they will get it done!