| abstract |
A carrier having a suitable degree of electrical conductivity is provided for fine tourmaline powders so as to enable their permanent electrodes to be utilized to the maximum. A tourmaline carrier is made up of fine tourmaline powders having a diameter of about 0.3 to 5 microns, esp., about 0.5 to 3 microns and a carrier material for carrying said fine tourmaline powders, said carrier material having a direct-current electrical resistance value or volume resistivity lying in the range of about 104 to 108 OMEGA xcm, esp., about 105 to 107 OMEGA xcm. |