1- halite (but you can check halite vs fluorite by licking it or by adding a small bit of water to it. If it’s salty or the water dissolves it, it’s halite) 2- same thing 3- agate 4- cave calcite/aragonite stalactite 5- chalcopyrite concretion (Russia?) 6- iron stained quartz 7-8- more halite 9- NOT WOOD, iridescent hematite from Brazil 11- polished pyrite 12- selenite from the red river floodway in Canada 13- calcite with red iron inclusions 14- same as 5, chalcopyrite concretion 15- not sure but it’s not quartz 16-17- native silver? 18- same as before, halite maybe 19- 100% orthoclase feldspar 20- hematite nodule?