Journey to the center of the Earth: Making crystals

The lava, porous in places, was covered with little round bulbs; crystals of opaque quartz, decorated with clear drops of glass, hung from the vaulted ceiling like chandeliers, and seemed to light up as we passed. It was as if the spirits of the underground were lighting up their palace to welcome their guests from the Earth.

‘It’s magnificent!’ I shouted in spite of myself. ‘What a sight, Uncle! Look at the colours in the lava which go from reddish-brown to bright yellow absolutely continuously. And these crystals that look like luminous globes!’

‘So you admire all that, my boy? You will see lots more, I hope.’

Jules Verne: Journey to the centre of the Earth

Crystals are a special kind of solid material where the molecules fit together in a repeating pattern. This pattern causes the material to form all sorts of unique shapes.

Crystals can have very flat surfaces called facets. They can form geometric shapes such as triangles, rectangles, and squares. The shapes are a direct result of the type of molecules and atoms that make up the crystal. Smaller crystals and larger crystals that were formed of the same molecules and in the same method should have similar shapes.

The process of crystal forming is called crystallization. Crystals often form in nature when liquids cool and start to harden. Certain molecules in the liquid gather together as they attempt to become stable. They do this in a uniform and repeating pattern that forms the crystal.

In nature, crystals can form when liquid rock, called magma, cools. If it cools slowly, then crystals may form. Many valuable crystals such as diamonds, rubies, and emeralds form this way. Another way crystals form is when water evaporates from a mixture. Salt crystals often form as salt water evaporates.

Can we make crystals? Of course. A good example is when saltwater is left to dry. The moisture will slowly evaporate and the only thing that is left is the salt. Salt appears in crystallized form.

Another example is to grow ammonium phosfate or copper sulphate crystals. Both of them are safe chemicals for producing a mass of crystals quickly. The first one is a white powder that yields clear crystals; the second one is a bluish power that forms beautiful dark blue crystals.

To get the crystals we have to stir salts into boiling water until the powder is completely dissolved. Put the solution into a container in a location where it will not be disturbed. If we want to get large crystals, let's try to cool the solution slowly from very hot down to room temperature. If we want big crystals we can take a small single crystal and place it in a new growing solution.

Good luck!!

And here, our first results. Beautiful crystals!