Crystal growing

Crystal growing is the hobby of producing crystals of various compounds. Crystals may be grown for other purposes, such as X-ray crystallography, but the amateur chemist is often interested in the aesthetic appeal.

Crystal growing can also be used for obtaining very pure chemical compounds.

Recommended compounds

Beginner

• Copper(II) sulfate crystals can be grown from supersaturated solution. CuSO₄ crystals are the most popular in crystal growing.

• Iodine can be sublimed in a closed vessel, and it will form deposits of purple to black crystals in the vessel when cooled. These crystals are small and fragile, but highly presentable. (orthorhombic, Cmca)

• Phthalic anhydride forms wiry, needle-like crystals when the vapor is allowed to condense. Phthalic acid can be used, and this will form phthalic anhydride in the process. Thicker crystals can be grown from a melt. (orthorhombic, Pna2₁)

• Salicylic acid crystals form rapidly when a methanolic solution is diluted with water. These crystals can grow to impressive sizes. (monoclinic, P2₁/c)

• Sucrose can be used to grow rock candy. (monoclinic, P2₁)

Intermediate

• Sodium chloride is somewhat difficult to grow in large crystals due to the fact that its solubility is only slightly affected by the temperature, but not impossible. Simply introducing a seed crystal in a large volume of supersaturated NaCl will yield some pretty square crystals. However it takes a while to grow large crystals.

• Sulfur crystals can be grown from hot toluene or xylene. Carbon disulfide can also be used as a solvent, though it's harder to find than the former two.

• Terbium acetate crystals are colorless but fluoresce bright green under ultraviolet light. (triclinic, P-1)

References

Relevant Sciencemadness threads

• Crystal Growing

• Chemicals for crystal growing