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W17 Rock candy from fifferent samples of household sugar
Candied sugar has its origins in India and Persia. Arabic writers in the first half of the 9th century described the production of candy sugar. Crystals were grown as a result of cooling supersaturated sugar solutions. In order to accelerate crystallization, confectioners later learned to immerse small twigs in the solution for the crystals to grow on. (http://en.wikipedia.org/wiki/Rock_candy).
In an earlier experiment sugar crystals were grown on the surface of a single rock candy dipping into a syrup made by cooking juice from sugar canes (Photo 4 and 5).

Now you will dissolve different samples of household sugar in distilled water containing a tiny quantity of food dye. After transferring to blisters the samples are observed during the coming weeks.
Material
Blister, 6 broad ampoules with stoppers, small can and candle burner (Photo left), Insulin syringe (1 ml), Drinking straw spatula, food dye (Cochenille red A E124, Azorubin E122), distilled water, different types of household sugar (sugar powder, brown sugar, rock candies...).
Experiment
1. Half fill the ampoules with sugar samples
2. From one of the ampoules add 1 ml of water mixed with a trace of food dye. Close and shake vigorously.
3. Collect the ampoules in a can and heat them on the candle burner.
4. Check whether the sugars are completely dissolved..
5. If some solid remains, add drops of water and go on heating. If the sugar is completely dissolved remove the stopper and go on heating.
6. Distrbute the hot solutions on the blisters (Photo 2).
7. When the content of the blister is completely solid (Photo 3), press it out.
Observation
No difference between the samples in the blisters.
Explanation
All samples of household sugar consist of the same particles. Therefore they separate as crystals of the same shape.