Johntoy make your own crystal Are you curious, do you fancy a physics experiment and do you want to make your own crystal? Do it with this Science Explorer Crystal Making. Fill the cup with warm water, stir the Crystal powder through it, let it rest and then put the base stone in it. Wait a day and watch your crystal grow and grow, after seven days the crystal has grown. Wow, what a beauty! Specifications: Colour: green Material: plastic/stone Gender: junior Age: from 8 years Diameter growth container: 8 cm Contents: 1 Growth container 1 Stone 1 Bag of coloured Crystal powder 1 Stirring stick