Edison Pearls are freshwater pearls from China and can become quite large. Usually around 11 and 16mm but 20mm is also possible.

Edison pearls inventor was Thomas Edison who was very persistent in developing a technique to compete with the more expensive Tahitian and Southsee Pearls. Pearls are grown in controlled freshwater environment. The pearls have a very thick nacre and high luster that’s competitive to the more expensive salt water pearls. 

The purple necklace in the picture has an interchangeable clasp made of a larger size Edison Pearl. This clasp can easily be used for other necklaces as well, or can be altered for another clasp to change the look of a necklace.