Alum grow quickly sometimes making visible crystals within a few hours.
Table salt crystals.
Salt is a mineral composed primarily of sodium chloride nacl a chemical compound belonging to the larger class of salts.
Table salt takes a few days to grow.
Buy it at a pharmacy.
You can see the shape of a salt crystal under a microscope and you can grow your own salt crystals for fun or for a science fair.
Iodized salt won t work as well but will still form crystals.
We also made coloured salt by adding a little food colouring.
Salt in its natural form as a crystalline mineral is known as rock salt or halite salt is present in vast quantities in seawater where it is the main mineral constituent the open ocean has about 35 grams 1 2 oz of solids per liter of sea water a salinity of 3 5.
Table salt also known as sodium chloride is a crystal a symmetrical solid substance made entirely of the same material.