Crystals

By Maddy Long

crystals after 2 days (in group beaker)

Procedure:

Day 1:

1. Make sure all apparatus is clean and dry.

2. Place approximately 25 g of potash alum in a beaker (250 ml or bigger) and add approximately 170 ml of hot water.

3. Stir the mixture until all the crystals have dissolved.

4. Filter the warm solution through a filter funnel (in which filter paper has been inserted) into another clean beaker.

5. Cover the beaker of solution with the watch glass or fresh filter paper and set aside in a cool sheltered place and allow it to stand undisturbed overnight.

6. The first beaker and funnel can be washed and dried and the residue and filter
paper used for filtration discarded.

7. Take photos and measure level.

Day 2:

1. Observe the beaker of solution.

2. Carefully decant
the clear solution above the crystals into a clean beaker and set it aside for later, leaving the crystals behind in the other beaker.

3. From the bed of crystals, one good symmetrical crystal or group of crystals needs to be selected to act as “seed” for your big crystal.

4. Using a plastic spoon, spatula, tongs or tweezers, transfer the selected crystal to the beaker containing the decanted solution,
trying to place it centrally in the beaker.

5. Cover the solution with a loose-fitting paper hat that permits water to evaporate slowly whilst keeping out dust.

6. Take photos and measure level.

Materials Day 1:

25g of
potash alum

2 beakers

170 mL of hot water

Stirring rod

Filter funnel

Filter paper

Watch glass/filter paper

Camera

Materials Day 2:

Beaker

Plastic
spoon/ spatula/ tongs /tweezers

Loose
fitting paper hat

Camera

Crystal Questions:
What is a Crystal?

A Crystal is a mineral, generally made of transparent quartz in a shape of a cubic symmetry or a glass that is clear, colourless and of high quality.

What substances can be used to make crystals?
There are many substances used to grow crystals for example, potassium aluminium, borax, copper sulphate, table salt, baking soda and rock candy to name a few.

What are some examples of Crystals in nature?

There are three types of crystals that occur in nature for example, ice crystals, stalagmites, stalactites and mineral crystals or gemstones.

What household items can you also grow Crystals from?

You can grow crystals at home really easily all you need is table salt or sugar, distilled water, a heat resistant glass, stir rod, pan, a heat source, pencil, string and a paper clip. These are some basic materials that you can find around the house to grow your own crystals on a piece of string.

Explain the process of Crystal growth?

Crystals grow when in hot water by adding a solution like salt, sugar or Potassium aluminium sulphate. You need to leave the crystals where there is not direct sunlight but out of the way of children and pets. The next day or two you should see that tiny little crystals formed in your jar.

Explain how crystals can grow in different shapes and sizes?

It depends on 2 factors

- The internal symmetry of the crystal and

- The relative growth rates along the various directions in the crystal

These two factors depend on how fast it grows and the shape and size it is.

Outline a few different types of crystals?

There are three basic types of crystals they are called single crystals, Poly crystals and Liquid crystals.

Single crystal - are any solid object in which an orderly three-dimentional arrangement of ions and atoms or molecules is repeated through out the entire volume. for example quartz and gemstones are often called single crystals.

Poly Crystals- They are solids that are composed of many crystallities of varying size and orientation.

Liquid Crystals-Liquid crystals have a cerian crystalline characteristics, especially different optical properties in different directions when exposed to an electric field.

What effects do crystals have on light travelling through them?

When light travels through the crystals the light is refracted from each angle and then dispersed at random giving it that 'sparkling' look to it.

What are the optimal conditions for growing crystals?

Crystals grow best when they are in the light but not the direct sunlight. Crystals do not grow very well when they are in pitch darkness. Use a large beaker or jar to give the crystals room to grow.

My Crystals after 3 days

Final Crystal:

My crystal started to grow after the second day. After I left it for 2 weeks I did not see much improvement in the size or shape of my crystals, instead I noticed lots of little microscopic crystals which started to form in the bottom of my jar.

My crystals were hard to take a photo of with the ruler next to it because my crystal didn't grow up but started to grow around the base of my jar. In the end my crystals were very flat but long because they connected together to form a chain like structure.

The properties of my crystals were that they transparent and that they sparkled in the light. The crystals were small, flat and had many irregular shapes and angles to them.

Crystals against a ruler

My crystals in direct sunlight with shadows (Creative Photo)

GAME!!!!!

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