There are many different kinds and models of electronic metal/mineral detectors to be found on today's market. This is a guideline to give you the basic knowledge to help you choose the proper detector for your prospecting needs, and to help you use your metal detector as an effective prospecting tool.
Types. The crystal detector consisted of an electrical contact between the surface of a semiconducting crystalline mineral and either a metal or another crystal. The construction of the detector depended on the type of crystal used, as different minerals varied in how much contact area and pressure on the crystal surface was needed to make a sensitive rectifying contact.
I've been metal detecting for around 15 years now and in that time have owned several machines: C-Scope 1220xd, Whites Eagle Spectrum, Garrett Ace 250, Whites Prizm 4, etc etc. Recently, after reading several reviews on the internet and having a chat with a detectorists shop owner I decided to buy a Golden Mask 4.