Home > Chemistry > Growing Crystals

Growing Crystals

By: Suzanne Elvidge BSc (hons), MSc - Updated: 24 Aug 2012 |
Crystal Salt Sugar Epsom Salts Allum

To grow crystals, you need to start with a saturated solution – water that has as much, sugar, salt or whatever crystal ingredient dissolved in it as it possibly can. Gently and carefully warming the solution in a saucepan, in a bath of hot water or on a radiator and stirring it will help more ingredients dissolve into the water.

To grow small crystals, leave the solution in the glass or pour it into saucer and let the water evaporate, leaving the crystals behind, or soak a piece of cardboard in the solution and leave it to dry. Pour the solution onto a hot glass dish or hot baking tray to get sheets of crystals.

To grow a string of crystals, hang a thread or string from a wire, toothpick or pencil balanced on the top of the glass into the solution and leave the crystals to form.

To grow a larger crystal, use a small crystal as a seed crystal, either grown on a string, or tied on to a piece of nylon fishing wire. Hang this in the solution in a clean container. Put the glass somewhere quiet, where it will not be knocked. If your crystal starts to dissolve, or isn’t growing, the solution probably isn’t saturated enough.

To grow stalactites and stalagmites, fill two jars with a saturated solution, put a strip of fabric between the two jars with the ends in the solutions. The middle of the strip should hang a bit lower than the tops of the jars. Let the solution drip from the middle of the strip into a saucer – a stalactite should hang from the strip, and a stalagmite start to form in the saucer.

Once the crystal has finished growing, keep it in a dry container.

It is probably a good idea to wear gloves when handling all the solutions (except salt and sugar), and do not drink any of the solutions (even ordinary salt at very high concentrations could make people ill).

Crystal Shapes

Crystals are made from repeated patterns of molecules, and grow layer by layer. Different solutions will make crystals in different shapes. Some might be cube shaped, others might grow in columns.

What Crystals Can You Grow?

Many ingredients for growing crystals can be found around the house or in grocery shops, supermarkets and chemists.

  • Salt (sodium chloride) is used to flavour food (but not too much – it’s bad for your heart).
  • Epsom salts (magnesium sulphate) is used in bath salts and in gardening.
  • Bicarbonate of soda (sodium bicarbonate) is used in cooking and in eco-friendly cleaning.
  • Borax (sodium borate, sodium tetraborate, or disodium tetraborate) is used in eco-friendly cleaning.
  • Sugar crystals are known as rock candy – try adding flavourings and colourings (and watch to see if these change how the crystals grow).
  • Alum (aluminium potassium sulphate) is used as an antiseptic and to stop bleeding, for example after shaving, and occasionally used in cooking.
  • Washing soda or soda crystals (sodium carbonate) are used in eco-friendly cleaning.

You might also like...
Share Your Story, Join the Discussion or Seek Advice..
Why not be the first to leave a comment for discussion, ask for advice or share your story...

If you'd like to ask a question one of our experts (workload permitting) or a helpful reader hopefully can help you... We also love comments and interesting stories

(never shown)
(never shown)
(never shown)
(never shown)
Enter word:
Latest Comments
  • simran panaich
    Re: Soap and Detergent Chemistry
    thnx!! It helped me a lot !!! THank YOu so much
    6 June 2019
  • Mar2
    Re: Why Oil and Water Don't Mix
    I am doing this as a demo for homogeneous mixture examples. It really helps, it is interesting, and thank you so much for it!!!
    5 June 2019
    Re: Why Oil and Water Don't Mix
    Why does the food coloring mix with the water i did not quite get iy
    31 May 2019
    Re: Looking at Soil Profiles
    This thing is stupid. I am a doctor and I know better then you do! I will do something about this website if you don’t change the…
    25 May 2019
  • Alice Picello
    Re: Looking at Soil Profiles
    25 May 2019
  • Rea
    Re: Making an Emulsion
    I have always wondered about the Earth. My teacher gave us this website to read about why water and oil don't mix. I started looking around on…
    16 May 2019
  • Candytashy
    Re: Looking at Soil Profiles
    Thanks so much for this post .it really helped me .made my homework much easier and l have learnt a lot from this post
    25 March 2019
  • Rajput
    Re: Pulling and Pushing: Magnetic Attraction
    Kya kisi chemical ko copper me mix karne se iron or steel ko push kiya ja sakte hai. Yadi ho to formula batye.
    25 March 2019
    Re: Soap and Detergent Chemistry
    Thanks you so much because you help different students especially science who went be a perfect a part of chemistry
    22 March 2019
    Re: Soap and Detergent Chemistry
    Thanks you so much because you help d/f students especially science who went be a perfect a part of chemistry like me.
    22 March 2019