I've got a really good lead on some substrate for my new 55 gal tank with an odd ballish theme including some Polka-Dot Loaches. A friend of mine has mineral rights for some mountains in colorado where he mines for gold flake. He has ton of 2 and 3 mm rocks from sifting. It contains mostly granite with quartz, garnet, and some shale. He did the vinegar test for me and said there weren't any bubbles or fizzing going on. Its fairly round but it does a some square like pieces in it. He said it looks really good with the grey,red,and clear quartz crystal in it, Do you guys thing that that will work well for my tank? Thanks for your thoughts.