This is an Anglo-Saxon buckle.
It’s quite small (4cm x 2.5cm) and would have been attached to the end of a leather belt to fasten a cloak or other item of clothing.
Made of bronze, it was originally gilded (covered in a thin layer of gold) Can you spot any traces of gold in the photo?
It’s decorated with a deep red semi-precious stone called a garnet. These were imported from Sri Lanka (a large island off the south coast of India) thousands of miles away, showing the extent of trade routes in Anglo-Saxon times.
It was found in one of the graves at Dover Hill Anglo-Saxon cemetery, Folkestone when it was excavated by archaeologists in 1907.