Gold trapped in the cracks can be encrusted close to the walls or mixed with sand and pebbles, making the gold difficult to see and then extract. Crevicing requires a lot of patience to achieve positive results.

Then I came to a section of recently exposed gravel that looked unworked. Water seeped out all around, making the ground beneath a sea of slick mud.

These are entry-level machines designed with gold prospecting in mind and with the ability to handle mineralized ground and see nuggets of a grain or so in size, perhaps smaller.