Is quartz stone with orange dirt with gold glitter in safe to put into a tropical fish tank?
Quartz is relatively non-reactive in water unless you’ve got a high pH. The glittery stuff is probably flakes of weathered mica (these will look like thin bits of plastic, gold flakes are thicker) – again not a problem. The only thing that I would be concerned about is the “orange dirt” and it’s composition. Orange dirt might be a high concentration of iron (which may also bring sulfur with it and lower the pH), or it could be decomposed feldspar (the third component of granite, along with quartz and mica). It’s relatively non-reactive, but if it’s decomposes to the point where it’s more like soil than rock, if it softens in the water, it will release the mica in it and you’ll get “glitter” floating everywhere. Since you haven’t removed it all, I’d recommend using a warm bath with oxalic acid (see if you can get this at a drugstore or through a lapidary website) and a soft toothbrush to remove the rest. Just rinse well before adding it to the tank.
