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

• Bismuth crystals can be made relative easy my melting bismuth metal in a pan/pot and then allowing the surface to gently cool, before breaking it, pull it out from the pot, remove the excess liquid metal, flip it upside down and allow the crystals to cool in open air, forming nice colored patterns.

• 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, and it's considered to be the best solvent for sulfur, though it's a lot harder to find than the former two.

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

Advanced

Crystals of insoluble compounds (like silicon dioxide/quartz, barium carbonate, etc.) can be done via hydrothermal method.

References

Relevant Sciencemadness threads

• Crystal Growing

• Chemicals for crystal growing