Although there's no such Diamond detector thing while the "best gold detector" on the market i have compiled a listing of handy tips on the best way to get the very best out of yours.
1) Always bring plenty of water to your treasure hunt: Always, always, always bring more water you then think you need. Dehydration can and will kill you if you do not respect it. once again. ALWAYS TAKE PLENTY OF WATER.
2) Check the current weather the day before a hunt: Gold detectors could be servery damaged by bad and damaging weather so make sure to keep them out of heavy rain or snow.
3) Do not step on other treasure hunters toes: - Unfortunately in this hobby, sharing is seldom viewed as courtesy. Avoid other treasure hunters areas or it could get ugly.
4) Always bring extra batteries for the metal detector: You will feel a bit silly if this happens to you (I know i did) so do not let it happen. Take a spare fully charged battery to keep you choosing longer.
5) Check regulations: If going gold detecting in other countries do not forget to check on their laws. They may possibly not be the same as your native country
6) Do not discriminate: Now plenty of people call me crazy for saying this but I would certainly dig up fifty items of trash and find one good treasure then potentially miss something of interest. If your detector is not finding anything reduce your discrimination. Sure you'll pick up trash but, you also may locate hell of a find that you'd of otherwise missed.
7) Get rid of trash: Make sure to dispose your entire trash you discover in a environmentally sound way. This serves two purposes:
1) keeps the surroundings clean (remember to always respect the land around you)
2) Moreover it keeps you from detecting the exact same trash time and again.
8) Venture out on a hunt after rain: Now most of us know that water is a good conductor but many individuals don't put two-and-two together as it pertains to searching for gold. After rain the bottom becomes wet and becomes a better conductor for for electricity meaning the detector can "sense" metal objects (weather they are coins or gold) a lot deeper and clearer. Give it a spin you might be surprised.
9) Work with a coil cap: Once again sounds simple yet plenty of people do not use them. Coil caps (Simply a protective cap that goes over your gold detectors coil) are quite cheap when comparing to a fresh coil. you can pick them up at your neighborhood detector store or even amazon quite easily.