Keep the young scientist happy for hours with this stone’s fascinating qualities. Popcorn Rock is a special variety of limestone mined in Utah. Simply submerge your rock in white vinegar and watch as a beautiful crystal garden develops over the next few weeks. These acetate crystals grow from the evaporation and reaction with the acetic acid from the vinegar. Makes a perfect gift, school science project or even a chemistry/geology learning tool. Individually packed for quick retail display. Ideal item to add to our Rock and Mineral Spinner Bin!