A squirt bottle helps you see what you've got, after it's out of the ground, but it usually only makes a mess earlier on in the digging. Bring your own food and water, hat, sunscreen, cookstove or firewood. There is no water on the mountain. There are outhouses. There are several small travel trailers available for use of diggers on a space available basis.
Visitors often join forces and share companionable potluck suppers.
If you're staying over, bring a beach chair to lean back and look up at the stars in the desert night. I was staying in one of the little travel trailers, and watched the constellations moving across the sky outside until I got tired, then watched in my sleeping bag through the window until I couldn't keep my eyes open a moment longer. There is no light pollution, and the brisk breezes keep the sky clear of other visible pollution. If you've got a portable UV lamp, bring that for night looking too. Fire agate doesn't fluoresce, but the calcite around it sometimes does, as well as other materials occasionally.