What is the best way to clean raw rocks

I lick mine. 100% usda recommended minerals and vitamins.
Not recommended for green or red rocks though as some of those have chemicals you shouldn't be licking. (copper and mercury)

Tony

lickem watch out for the dino turds though they taste bad!!!

Hydrochloric (muriatic) acid will remove carbonates from the agate really well.  There are several acids that can be used to remove iron stains.  These include hydrochloric, phosphoric, oxalic or citric acids.

Remember though that if you are not familiar with handling or using these chemicals research their handling and safety issues thoroughly first.

I usually wash with the hose on my special cleaning bench which is assembled outside each spring. If the crud on the rocks is something like heavy mud, I soak the stuff in buckets for a few days to saturate the mud and then hit it with the hose. Afterwards if it has something undesirable on it which I can dissolve with acid, I sometimes do so.
Usually though, I will not use the acid unless it is of benefit. Sometimes the hard crud is not going to hurt anything and is easily removed when saw time comes.

There are times however when placing a small piece in the acid is used as a tool for identification or clarification.

Here are some basic tips for working with acid.
1. Use it outside only.
2. Try to keep the operation downwind from your work area and everything else if possible. It produces fumes which can corrode everything they touch.
3. Keep it away from metals. Especially aluminum. Aluminum reacts violently with acid.
4. Eye protection.
5. You will want the proper gloves.
6. Babysit the process.
7. Keep all children, morons, jackasses, and fools away from your operation.
8. Keep the hose handy. Clean, clear water is your friend in case you need to decon in a hurry.
9. When mixing acid, water goes into the container first. Acid is added to the water. Never the opposite.
10. Plan for an emergency with the chemicals ahead of time.

If I missed something or mis-typed something please point it out. Additions are encouraged.

I soak mine in beer
they may not come clean but
happy rocks
mostly

I use the pressure washer at the coin op car wash. It will come off in the tumbler too.

Or you could put them in a tube sock (tie it closed) and use herchenx method with no clangers.

Ran across this idea the other day, had to try it; homemade ultrasonic cleaner. Not knowing if it would work, I did it on the cheap using a bucket with a brittle top and a palm sander we got with some stuff at a contractor-going-broke sale [$2]. I cut a couple pieces of sheetmetal 1/2" wide and drilled them. I attached the sheetmetal to the sander using the grip rods normally used to hold the sandpaper, centered it on the bucket bottom, and match drilled the bucket for the screws. Attached sander to bucket using 1/4" pan head screws so as to get a bigger head diameter. Made gaskets under each screw head by cutting a little piece of innertube and punched a 1/4" hole in the center. Hex head bolts with washers would work too, with the gasket under the washer. To support this bucket, I bent the bucket bail straight and cut it into 3 equal pieces about 8" long, bent an inch over to have a place to grab for removal, and used them and the elect cord between this bucket and another that I slipped this one into, so the two buckets wouldn't wedge together. Pulled the rods and the buckets came apart. This keeps the sander from resting on anything. Found some very craggy, dirty, unwashed rocks out back, mixed 2 tbs. Dawn in a gallon of hot tap water, put the rocks in and ran it for ten minutes. The thing works. Looked it at after the first run, then tried it again for another ten minutes, very little more came off the rocks. This has to be run on a soft surface [lawn] so the assembly doesn't walk off. It won't take the "embedded in the rock" dirt off, but it did a good job on dirt-mud. Works better than a garden hose with a pressure nozzle on it, and I didn't get soaked. The noise level is about the same as running the sander in it's intended use. I used a Dremel to cut the center of the bucket bottom flat.