Growing Alum Crystals

Materials: ★★☆ Available in most school laboratories or specialist stores
Difficulty: ★★☆ Can be done by science teachers
Safety: ★☆☆ Minimal safety procedures required

Categories: Crystals, Water and Solubility

Alternative titles: Potassium Alum Crystals

Summary

Potassium alum powder is dissolved in hot water to form a saturated solution that produces clear, diamond-shaped crystals as the solution cools and evaporates. By carefully selecting and growing a seed crystal, you can form large, pure alum crystals within one to two weeks.

Procedure

  1. Dissolve 90 g of potassium alum powder in 500 mL of hot water, stirring until all the alum is dissolved.
  2. Filter the solution through a coffee filter or tissue paper to remove impurities and allow it to cool to room temperature.
  3. Sprinkle a few grains of alum powder into the cooled solution and leave it undisturbed for 2 days. Small seed crystals will begin to form.
  4. After 2 days, pour about 50 mL of the solution into a shallow dish and the remainder into a transparent jar, leaving any crystals behind.
  5. Let crystals form in the dish for several days until they reach about 0.5 cm in size. Choose the clearest and best-formed crystal as your seed crystal.
  6. Tie the seed crystal with fishing line (or suspend it from a stick) so that it hangs in the jar of remaining solution without touching the sides or bottom.
  7. Place the jar in a stable, dust-free environment and allow the crystal to grow as water slowly evaporates.
  8. Once the crystal reaches the desired size or the water level nears the crystal, remove and dry it gently with tissue paper.
  9. To preserve clarity, coat the dried crystal in clear nail polish or store it in an airtight container with alum powder.

Growing Alum Crystals - UnitedArtAndEd: https://www.youtube.com/watch?v=39BPnWsawxI

How to grow Alum crystals! - Huge alum crystals diy in supersaturated solution. - DestructiveCreativity:


📄 The Best Way to Grow Alum Crystals at Home - Crystalverse: https://crystalverse.com/grow-alum-crystals-at-home/

Variations

Safety Precautions

Questions to Consider