Remember "Magic Rocks"?
This is the same thing, except that you can create them from scratch... Thought with winter still upon us, this might be a welcome passtime to share with any restless children around the house

You'll need
A brick or or a couple of lumps of bituminous(soft) coal, bashed into walnut
sized pieces, arranged in the center of a 6 inch dish or shallow bowl.
Food colouring
And, mixed in this order,
4 tablespoons of PLAIN (not iodized) salt
4 tablespoons liquid bluing
4 tablespoons water
one tablespoon ammonia
Stir the mixture until the salt dissolves and pour over your brick/coal pieces
Use an eyedropper to drip different shade of food colouring onto the damp lumps... in a few hours, wispy coral-like crystals will form in the shades of the food colouring you used..
handle the dish gently and they will last for a few weeks.
Important note: DO NOT reuse your brick/coal chunks.. if you do this more than once, use fresh elements each time.