Thames & Kosmos Crystal Growing Experiment Kit. Grow dozens of dazzling crystals and conduct 15 illuminating experiments with this classic science kit by Thames & Kosmos. Experiment with four chemically different crystals each with different properties, including potassium alum crystals that form regular octahedrons, rapidly growing sodium sulfate crystals, long needle-shaped sodium acetate crystals, and plaster which is made from gypsum crystals. Mold fun plaster shapes, including stars, lightning bolts, dolphins, and pyramids, and grow layers of crystals on them. Use dyes to form colored crystals, and mix the dyes to grow a rainbow of custom colored crystals. Display your crystal creations in a clear treasure chest with a locking lid. Mold your own geode - a hollow rock with crystals growing inside - and create a beautiful crystal cavern inside. Experiment with growing crystals rapidly and slowly, and observe how that affects the crystal structures. See if you can grow one giant crystal and many small crystals on the surface of a rock. Measure how the crystallization of solids out of a solution, and the dissolution of crystals back into solution, affect the temperature of the solution. Learn about the energy of crystallization. Investigate solutions, crystallization, and the chemistry of crystal growing. Learn about the structures and geometries of different crystal shapes. This kit is thoroughly tested and safe: Over one million units of this kit have sold worldwide. A full-color, 32-page experiment manual guides your experiments in crystal chemistry and Earth science.