If you perform a small search on the Internet, you'll come across a wide range of formulas and detailed instructions about how to make your own lava lamps at home. Though it is definitely a lot of fun, the whole experience could cost you a good deal of money; unless you are really after some unique pass time, it is advisable that you buy ready-made lava lamps from a specialty shop.
The most difficult part in the creation process of lava lamps is the motion feature that the lamp needs to have to show authenticity. First of all, such lava lamps require heat control that is automatically incorporated in the manufacturing design of the items bought from the store; otherwise, in home use some form of heat output control is required in order to avoid overheating.
If liquid wax is out of reach, then oil is the next choice you've got to simulate the lava in the lamp; but since two kinds of liquids are required for the internal structure of the device, you'll have to complete it with some form of regular alcohol like the one produced for medical use. Home made lava lamps should have the oil at the bottom which will afterwards rise in different shapes when the alcohol is added.
There are no restrictions in terms of the liquid container used in the design of home-made lava lamps; the only condition to be followed here is that the shape of the device be pleasant and artistic enough to be used afterwards. In order to get the great colors specific to the lava lamps you may have use some pigments, and organic food colors are often a good choice for the matter; after all bubble making and nice shape creations are the set goals in the design of individual lava lamps.
The only problem with lava lamps made at home is their safety on the long and short term as well. If you consider the fact that the glass container may break at some point if you don't take care of heat control, would you risk wasting the time over a decorative item you'd not be able to use on the desk or in the children's room for safety reasons? Therefore, unless you have some experience in the making of lava lamps, it would be better to simply buy one from the store instead of wasting time and money.