Answer:
Blue blocks contain NaCl (table salt), Cobalt and Iodine.
Red blocks contain Salt, Iron and Iodine.
Brown blocks contain Salt, Cobalt, Iodine, Iron, Zinc, Copper, Manganese, Molybdenum, Potassium and Magnesium (guessing on the last two minerals)
Black blocks contain everything that the brown blocks do, plus Selenium.