Well, the short answer is, it isn’t. Although Himalayan salt, like most salt does contain some water molecules locked up within its crystalline structure, these will only be liberated by exposing the ground salt to extreme heat for some time.
The water you see coming from your lamp is in fact water vapour from the air. Salt is a drying agent – it attracts moisture from the air and absorbs it.
If you are using your lamp in a very humid environment, you might find that there is so much water collected by your lamp in this way that the exterior of it feels damp. In extreme humidity or dampness, this water may collect in such volumes that it runs down the outside of the lamp and gives the impression that the lamp is leaking.
Just to be clear, your lamp is not leaking!
However, it may be wise to place your lamp on a plate so that any water collected by your lamp in this way collects in the plate, rather than around the base of your lamp. If your lamp is on a varnished surface of some kind then this water could leave a ring on your table or shelf where your lamp is placed.
The bottom line is that if your lamp is collecting water in this way, it is a good thing. Excess moisture in the air is not always good for your health since that dampness can lead to the growth of mould and therefore the spreading of mould spores throughout your house. This, in turn, can lead to all kinds of infections, making the lives of those living in the damp house pretty miserable.
If you are experiencing persistent infections of the ears, nose, and throat, you might find that excess dampness and moisture in your home is the problem.
In colder, wetter places, this can be a real problem in the winter, as the warmth and damp air from breathing leads to condensation on bedroom windows, which, in turn, can lead to the growth of black mould around the window frames and on curtains.
Salt lamps, because they collect water in this way, can really help with this kind of thing, especially because they also release negative ions into the surrounding air, which are extremely beneficial to health.
If you are experiencing excessive dampness in your home and persistent colds, then salt lamps are a great addition. Not only is their light warm and lovely, but between the absorption of excess moisture in the air, and the release of negative ions they can make a real difference.
You may want to consider getting a de-humidifier if your house is overly damp, and a salt lamp will help you determine if your house is very damp if you are unsure.
If you install a lamp and it consistently seems as if it is ‘leaking’ water, you may well have a damp problem. The solution is either to get a great many salt lamps (which is a nice option if you can afford them and have space) or to simply get a dehumidifier and get that running. Many dehumidifiers will also filter out mould spores and have an anti-bacterial filter.