Looking good.... I can tell this is going to come out nicely based on how you are giving it the time/attention it needs. I like to go this way too. I've set some tanks up in 2 hrs and some in 2 mo.. if you don't rush it you wind up with good results everytime. If it looks right on the 1st drop leave it. If it doesn't then play w/ it. When your brain hurts do something else and come back to it
Those are some nice rocks. Did you find them just that way... Or break a big one?
Are you gonna do a background? I always feel hg looks best with a solid backing... Like black brown or d. Blue spray paint. Being you can see through it.
I actually fond these rocks in a few places. A few in a dry creek bed and I got 2 more at the edge of the river by my house. For the small ones though I did end up breaking a rock. I cleaned the crap out of them, boiled them for a while and did the vinegar test they should be good to go. The background that I want is straight black. I think it really makes all of the colors pop when its all done and grown in. The Indian red sword is a good suggestion. I have been playing around with paint on my computer to kind of get an idea.