Sometimes you can tell what you have found as soon as you dig it up. Other times, it's not so obvious. That's when you have to start a different type of hunt - identifying your treasure.

There are many ways to figure out what you have. You may even need to use multiple resources to get a final identification.

Google Search
If you have an idea of what you have, a search for the item and comparing it to the images in the results may be as far as you need to go. If you have no idea, a Google search can still help by using an image search.

You'll want to clean up the find as best as possible then get a clear close-up digital snapshot. From there you can have Google search for visually similar images. The technology isn't perfect, but it could help you get a better idea of what you have.

There are plenty of books on artifacts for different eras or the type of find you are looking for available. You can typically match up finds pretty easily, especially coins.

Metal Detecting Clubs and Online Forums
Other metal detectorists are a wealth of knowledge. People usually have a specific kind of treasure that they look for and may be able to identify it for you, or at least point you in the right direction of where you might find more answers.

People who enjoy searching for and cataloging history so much that they have devoted many years towards the pursuit may be able to easily identify the era, material, or use just by looking at it. Sometimes they work for a museum, preservation society, the government, or even a restoration service. Other times they are collectors and enthusiasts that like to help out others.

No matter where you begin your search, it is a good idea to note the area where you found your treasure. Some places are known to have been used as a military camp or are sites of long-demolished buildings that could provide helpful hints to identify your metal detecting find.