vinegar test rock

I collected some rocks with my children out of a nearby stream. Can you identify any of them? I have already tested them with vinegar and also soaked them to see if they contain oil and all was good. Just curious what they are. :smile: I think #1 is granite and a couple others are quartz, but I...

I was in the mountains this weekend :) and I have found a couple of rocks :icon_eek: who I want to use in my second iwagumi :icon_roll attempt. I ask you all my friends to judge the rocks and give me a bit of advice. because at first i wash them with water after I make the vinegar test...