Medicine Stones or Gemstones? That is the question.

My Grandparents travelled overseas and brought home unique items. The stories were more interesting. These stones came from a family acquaintance sometime in the mid 1980's. He was from England. He gave these Stones to my grandparents during his visit. It was much later that I was told about these stones and how they came to be with our family. It was said that these were medicine stones. To be kept in the lived ones pocket to ward off sickness. Funny I don't recall either of my grandparents being ill during that time of his visit. Not was the Englishman of native American decent. Some of the stone's are opaque. Translucent. Almost smokey in appearance. Others are solid black.