"On December I took a trip to meet my family in Guerrero, Mexico. My grandmas boyfriend talked about finding these while out for walks in water streams. He has collected them over the years."
A: "They are spindle whorls. These are the weights for hand spinning yarn/thread"
This. Learning to sharpen your knife by hand is not easy at first, but it's worth it.
It detects the presence of an electric charge.