Salt lamps are made from large salt crystals that have been hollowed out to make room for a bulb or candle. The salt crystals for salt lamps are mined in Russia, central Europe and the Himalayas. When the light bulb or candle is lit, the heat causes the salt lamps to emit negative ions. It is believed by many that these negative ions have a positive health benefit. As with anything that has claims to health benefits, please consult your physician and use caution.
Leaving the lamp unattended
Never leave your salt table lamp unattended. There are risks of fire with both the candle version and the light bulb version. The candle can tip and start a fire, and any electrical device can spark to start a fire. If you leave the area, turn it off. You will still get any benefits available from the salt lamp when you are present in the room.
No Protective Base
Salt lamps attract water, so if there isn't a protective base attached, then water will accumulate at the bottom of the lamp. The bottom of the lamp is typically where the electrical cord is coming in for the light bulb. If the condensation from the outside of the lamp can't go into a protective base to evaporate, then it could cause some serious fire issues when it comes into contact with the electrical cord.
Base isn't securely attached
Crystal salt lamps can get fairly heavy. The base, in addition to catching the condensation that the warm salt lamp attracts, is what holds the lamp upright and keeps it stable. If the base isn't securely attached, then the lamp could be bumped and knocked to the floor. Not only could this be dangerous for whatever it lands on, but if the light bulb (or candle if it is a candle holder) is lit, then this could cause a fire.