Inert, though complex, mineral. One of its unique properties is that it is piezoelectric, meaning that it generates an electrical charge when under pressure, which is why it’s typically used in pressure gauges. Tourmaline is also pyroelectric, which means that it generates an electrical charge during a temperature change (either increase or decrease). However, none of this can take place in a cosmetic—and why would you want it to? For example, one of the results of generating an electric charge is that dust particles will become attached to one end of the tourmaline crystal. Who wants that on their skin?
There is a patent for using tourmaline to decrease the need for surfactants, but this patent is for a complicated device and the effect is not generated by the tourmaline itself. Here is a quote from U.S. Patent number 6,308,356, Frederick, et al. October 30, 2001, entitled Substantially Environmental-pollution-free Cleaning Method and Device Employing Electric Energy and Surface Physical Properties: "The treatment of water by the electrically polar crystalline substance tourmaline requires much longer time to fill up one washing machine tub than the effect lasts. This yields this process of batch treatment before use as impractical as a laundry solution. In the current inventive method the treatment is done simultaneously with the work of cleaning and in the same location as the work of cleaning is being done." In other words, it is a process that uses tourmaline in some way, but the cleaning is not a result of the tourmaline itself (the language is not clear). It doesn't translate to electrifying or illuminating your cosmetics, and especially not in the trace amounts this mineral is found in cosmetics. There is no published research showing tourmaline has any proven effect on skin whatsoever.