what sort of geiger counter do i need to check for alpha beta and gamma radiation in minerals im finding!?

i metal detect for gold and i,ve found some specimens of a silvery white metal, upon showing a friend who is an aircraft engineer, i was told they could be a natural occurring radioactive mineral and not to play with them until i find out! my question is, how do i know which type or brand geiger counter on ebay is the real deal! and can check all types of radiation? id much prefer to find out if these specimens are unsafe to handle, than to put my head in the sand and pull it out with a second head attached! lol

A gold leaf electroscope is cheaper and responds to all kinds of ionizing radiation, plus it uses no batteries. I think you can buy one from Edmond Scientific in New Jersey, or maybe in a local school supply house.

Metal Detecting Treasure Hunting Gold Silver