I don't know about the rest of you but I live in an area that is loaded with heavy black sands... Lumpkin County, Ga. Dahlonega Gold Belt...  When I first started I lost a lot of gold because  there was just way to much black sand displacing the, what  I call face powder gold... And, at least half of that black sand is magnetic... Every one always says that using a magnet will make you lose gold... To be honest, it does happen... If your like me I work hard for the gold and I want all I caught... It didn't take long for me to realize that working with a magnet and wet sand is the worst... Over the years I have accumulated a couple of metal pans and several plastic pans of assorted sizes... I seldom have a boatload of cons since I realized that my days of wrestling with a dredge hose just wasn't worth it to me...  Either sun dry your cons or throw a metal pan containing the cons on the campfire... If you throw them on the fire do not stand around and breath the steam because we all know there may be a chance of mercury poisoning...  Line your pans up and after the cons are cooled begin to lift and drop  the magnetized material from one pan to the next... You will notice that the black sand left in the first pan is finer and lighter than the magnetic sands moved to the next pan... Repeat this until all the magnetic material is in the last pan...  If there is a use for the iron sand I have several coffee cans of it...  Now use whatever method works best for you as usual for the rest of the clean up...  You will find that you will  get that really fine gold much easier and if that's all your getting you may be surprised at how much gold you were losing... Elad