Well, actually it isn`t... Practice refutes theory. And not every human is the same. If you feel that certain stones help you in certain situations, then it works for you and why should you stop with it? Not everything in this world can be explained with todays knowledge.

Todays knowledge is, that plants and humans emit biophotons. Originally discovered in 1920s by Alexander Gurwitsch, it was proven and measured by Fritz-Albert Popp in the 1970s in Germany. The wavelength is between 200 and 750nm. This phenomenon is not to be confused with bioluminescence, where e.g. male bugs emit visible light to attract female.
This ultraweak photon emission could be what is named the aura in indian philosophy.
This biophoton emission also means (according to the Wave-Particle Duality theory) that the human body is surrounded by a weak electromagnetic field.

Crystals, like quartz, interact with electromagnetic fields. This phenomenon is called piezoelectricity. It means, that eelctricity applied to a quartz causes an mechanical deformation of the quartz. The revers effect is that mechanical deformation of the quartz produces electrical energy. This fact is used to produce a spark in your lighter when you push a button.
So crystals can amplify electromagnetic fields, when going into resonance. This is used in the oscillating quartz in your computer which is kept in resonace and oscillates very accurate in a certain frequency.

So if there is interaction between electromagnetic fields and crystals, why should this be limited to electronic circuits and lighters?

Interaction between the human body and crystals is not proven, yet. Does this mean it is not there?
Crystals could amplify certain energy while weakening other energies, depending on the crystal structure. So if you feel that a crystal helps you having more positive energy and keeping away negative energy, this is maybe supported by science one day.
 In the meantime you have to try out, hold a crystal in your hand for several minutes and trust your feelings.

In the following we want to give you some information on gemstones and the powers and effects, that are associated with them.