MadSci Network: Earth Sciences |
Well it could be a couple of different things. Remember that sand is just very small rocks (2mm-1/16mm)broken up into little pieces. And rocks are just made up of minerals, which are chemcials and elements. And what typically 'sticks' to magnets? Anything composed of a ferrous material. Iron (Fe). So what is attracted to magnets? is black? and has a high Iron content? Magnetite for one. But there are others. Remember that the content of the mineral will determine the properties. Try collecting some of the black material. Enough for a small pile. Leave it out side. If it has enough iron in it, it should rust. This may take a while before you get results.
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