What is black magnetic sand?
Similarly one may ask, what is magnetic sand?
Each often contain a magnetic mineral called magnetite. Volcanic minerals and lava fragments commonly have magnetite in them. Magnetite is a type of iron oxide that is naturally occurring, and it is what makes black sand magnetic. This type of sand can be found on many beaches in Hawaii, like Punaluu.
Secondly, is black sand a sign of gold?
Black sands (mostly iron) can be and usually is an indicator of gold, but not always. Rule of thumb is you will generally find black sand with gold, but not always gold with black sand. However if you are finding gold and getting black sands with it, it would be worthwhile to try some and see what happens.
Although kinetic sand is non-toxic, eating large quantities of it can be dangerous which is exactly why small children should not be allowed to play with the sand unsupervised. The very properties that make the sand so much fun to mold and touch is the same reason why ingesting it could cause problems.