If you have a natural deposit of essentially black sand, then you might consider using The Gold Cube. According to what I have read, it is capable of getting rid of a lot of black sand in a very short time to produce a decent gold concentrate. It will still need more cleaning though.
Before that, try the Coca-Cola bottle test!
1 - Three-quarters fill the bottle with water.
2 - Top it up with a mix of your black sand and tiny white quartz pebbles.
3 - The pebbles will zoom to the bottom first, the black sand will follow and bury the quartz pebbles.
4 - Put the top on the bottle.
5 - Hold the bottle and b-o-i-n-g it against a wall.
6 - The quartz pebbles will suddenly wiggle and rise to the top of the black sand, together with other lights that are less easy to see.
7 - Gently tilt the bottle horizontal.
8 - Hold the bottle up above your head, and shine a light on the bottom of the bottle.
9 - If you are lucky, then gold will be visible hiding beneath the black sand.
A curious point to remember is that, often but not always, the gold in black sand is much smaller than the particles of black sand (magnetite etc). The reason for this is due to 'hydraulic equivalence', a strange concept but seemingly true.
Therefore when looking at dry black sand with a good lens (x20) or better a zoom x40-x100 binocular microscope, most of the gold is likely to be missed by eye at first glance. That's because the gold is so tiny and heavy it burrows under the black sand in a fraction of a second. To reveal the gold particles, I find the simplest way is to bend a paperclip (plastic coated is best) into an L-shape and then use the bottom of the L to stroke the black sand into a smear. With luck you'll see fine gold.
Another method, used by artisanal miners in some countries, is to spread dry black sand out on a smooth flat metal sheet. Then to hammer the black sand to crush it. The gold is not in the black sand but the black sand being brittle shatters and can be gently blown away, whereas the gold being malleable just spreads into a thin sticky malleable sheet.
Hope these suggestions help somehow.