Questions and Method
What is a Crystal?
A crystal is a build-up of chemical compounds that joins together in a constant arrangement allowing light to bounce off them. These chemicals form a solid substance which can be microscopic or quite large.
What Substance can be used to make crystals?
What are some examples of crystals in nature? What household
items can you also grow crystals from?
Household items you could use:
Explain the process of crystal growth?
Sodium and Chlorine atoms both share a
pair of electrons in an ionic bond. While in solution, the Sodium and Chlorine are
separated by water molecules. As the water evaporates from the solution, the Sodium
and Chlorine atoms begin to bond together, first as single molecules and then
the molecules bond together, forming crystals. Every molecule will form the
same shape crystal each time it forms. The crystal shape for salt is a cube
like a six-sided die.
Explain how crystals can grow in
different shapes and sizes?
Crystals can ome in other shapes than just cubes. For example, you can see triangle
shapes in crystals like rubies and amethysts. The unit cells for these crystals
are more difficult than in salt and they have a different shape, but the unit
cells still stack together in a regular pattern to make a crystal. Perfect
crystals have only straight edges, but most of the crystals we see in nature
aren't perfect. They often grow in confined spaces in the ground and don't have
the room to grow in even directions. So they may have some straight edges, but
look rounded or jagged in other places.
Outline a few types of crystals?
Diamonds, rubies, sapphires, and emeralds have been a popular type of
crystal for thousands of years. They are highly valued due to their beauty and
relative small amounts that exist in nature. There also opals which is an
Australian crystal, not so rare in the outback. Plenty are gathered each week.
Salt is used in day to day cooking and cleaning. Sugar is used in cooking also.
What effect do crystals have on light travelling through them? (Relate
to reflection, refraction, dispersion and diffraction)
Light behaves differently depending on which
direction the light is reflecting at the crystal. The index of refraction
depends on both composition and crystal structure. When light hits a crystal at
a certain point, there will be a reflection of bright light. In some
circumstances the light can be quite blinding, but it depends on the crystal.
What are the optimum conditions for crystal growth?
Warmth is the key to forming crystals. A
jar's surroundings should be warm also for optimum crystal growth. Warm air
temperature helps water evaporation, causing the crystals to grow more quickly.
Crystals will still grow in cooler temperatures, but it will take much longer
for the water to evaporate. Crystal growth also requires light. Again, the
crystals will eventually grow in the dark, but it will take a very long time.
Light evaporates water as heat does; if you put a jar of what you are using to
make your crystal you should have crystals forming in a minimum of a few days.
25 grams of potash alum
2x 250 ml beaker
170 ml of hot water
watch glass/more filter paper
1. Place approximately 25 g of potash alum in a
2. Add 170ml of hot water
3. Stir the mixture until the crystals have
dissolved, the solution may be slightly cloudy which is perfectly fine.
4. Filterthewarm solution through a filter funnel (with the filter paper inserted) into
the second 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 cleaned and dried and the waste and filter paper
can be thrown out.
2x 250ml beaker
(left over potash alum)
loose fitting paper hat
1. Observe the beaker containing the solution. The
bottom should be covered with a small layer of crystal because the solution is
2. Gently decant (pour off) the clear liquid above
the crystals into the clean beaker and set aside. Make sure the crystals are
left in the other beaker. If no crystals have formed overnight, you can seed
the solution. Do this by adding crystals from the original alum and let it sit
overnight again. You may also need to stir the solution with your stirring
3. Choose one good symmetrical crystal or group of
crystals to act as the ‘seed’ for your large crystal. Using your plastic spoon,
tweezers, tongs or spatula transfer the chosen crystal into the middle of the
beaker with decanted solution.
If you want the crystal to grow rapidly suspend the crystal with a nylon
thread tied to a pencil resting on the rim of the beaker.
5. Take a
picture of the crystal in line with the ruler so you measure its size and mark
the level of liquid in the beaker.
6. Record this in your logbook.
7. Cover the solution with a loose fitting paper
hat that allows water to slowly evaporate and keep out foreign particles. Keep
it somewhere where the temperature will stay constant.
2x 250ml beakers
1. Once a week record the level of liquid in the
beaker and without moving the crystal take a photograph of it next to the
2. Estimate and record how much the crystal has
NOTE: Try to avoid disturbing the crystal as much as
possible. Don’t touch the crystal with
3. If any isolated crystals appear you can remove
them gently with tweezers. If small crystals begin to form on your main crystal
dry and remove them with a tissue.
4. If the crystal isn’t growing anymore you can
create a new solution using the pervious steps and gently transfer the crystal
once the solution is room temperature. The solution may need to be left
overnight to cool before the crystal is added.
5. Once the experiment is over, remove the crystal
extremely carefully from the beaker, dry it with a tissue and measure its
length, width and height with a ruler. Compare the measurement to the original
size of the crystal in your logbook.
Today my group completed the practical component of the experiment! We gathered the potash alum, combined it with hot water and filtered the solution into a clean beaker correctly so hopefully tomorrow we will have some #awesome #crystals #beginning #to #grow!
I am throughly enjoying this crystal experiment and I know I will grow a #huge crystal in the future!
We haven't touched the solution since yesterday because the rapid growth of our crystals has meant we haven't needed to seed them.
Today is Thursday and today we are taking home our jars with crystal solution! #gottabecareful #don'twanttobreakit it is extremely important that #cmacca, #remdogga and myself chose a crystal each from our beaker and pout them into our own jar for the holidays! We also equally divide the Aluminium Potassium Sulfate solution into our jars. I chose a reasonably large crystal and hopefully it will grow into an even bigger crystal over the next 2 weeks! #supaexcited #crystalgrowing #producingdiamonds
Below is a picture of my biggest crystal on day 4! Lets get weerrkin! #growgrowgrow YAY It's currently 9 mm long!
It is Tuesday the 24th of September and it is my first time recording my observations about my crystal at home! #lotsofphun I have had my jar sitting on top of my shelf in my room, which is high off the ground where nobody will touch it. I have left the filter paper hat on top of the jar allowing some air to enter and leave the jar.
Since last week a lot of water had evaporated and smaller crystals have begun to appear surrounding my main crystal on the floor of the jar. I don't know how but some dirt has made its way into the jar but I don't want to disturb my crystal so I have decided to leave the jar alone. I took a photo and measured the amount of liquid solution in my jar to be around 1.5 centimetres deep!
I am sooooo #HAPPY because my crystal growth has progressed further (: #sad #jks #overthemoon #pleased Although it has grown 1.2 centimetres longer I think the crystal hasn't received enough sun so I have moved the jar to a lower shelf. The smaller crystals have grown a little more and the water level has dropped now recorded at 1 centimetre deep. I am hoping over the next few days the crystals growth BOOMS and I get some more B-E-A-U-T-I-F-U-L crystals! #optimistic
So it has been a good week since I last checked out and recorded on crystal growth and I'm sad to say the results were disappointing! The solution level has remained the same however some of the smaller crystals are slower beginning to join together! The 2 largest crystals would probably be around the size of a #plum #pip and the other 3 smaller ones roughly resemble #peas.
After leaving my crystals more exposed in direct sunlight for the past few days I have noticed a massive difference! Most of the liquid solution has now evaporated and numerous baby crystals have formed around the edge of the jars bottom. My largest conjoined crystal is growing bigger everyday and I can't wait to see the end result! #happy #crystal #growth #BOOMING #awesome
#YAY #MY #CRYSTAL #EXPERIMENT #IS #NEARLY #COMPLETE hahaha I am very pleased to say that my liquid solution has nearly evaporated and the large crystals in my jar have grown even more since I last recorded my observations! These photos down below show that in the next few days the liquid will be completely dried up and I will be able to take photos of my crystals out of the jar! I defiantly cannot wait to see the finished result! #yiiippeee
It is official! All of my liquid solution is #GONE that is right, it has evaporated #COMPLETELY! One on side of my jar where my large crystal is all the other smaller crystals are clumped around it making it look even bigger then it actually is. There are also some small rings of tiny crystals at around the base of the jar where the solution level would have been at one stage! #fun #experiment #science #crystals #thediaryofacrystal ! There is also some tiny specs of dirt in my jar, I do not know how that got into my jar but I will take them out with tweezers later!
Overall my crystal experiment was successful from the very start. My group #remdogga and #cmacca and myself #vjthedj formed the best overnight crystal solution in the class as well as having my crystals grow to 5cm long throughout the duration of the crystal experiment. I formed 4 large chickpea size crystals, 9 lentil sized crystals and hundreds of tiny crystals which formed around the edge of my jar. As well as completing a successful prac I had so much fun with a very different, more hands on experiment! The final dimension of my largest crystal was 5cm and it is located under the clump of crystals below.
Below this creative photograph shows many dimensions of the different crystals. I placed my largest crystals together in a clump as they broke when I had to get them out of the jar. The light is reflecting off the crystals onto one another and into the centre of them projecting light and giving them a mirrored effect. They are clear, glistening crystals.