The present invention relates to a method for the production of trichlorosilane by reaction of silicon with HCl gas at a temperature between 250 and 1100.degree. C., and an absolute pressure of 0.5-30 atm in a fluidized bed reactor, in a stirred bed reactor or a solid bed reactor, where the silicon supplied to the reactor contains between 30 and 10.000 ppm chromium. The invention further relates to silicon for use in the production of trichlorosilane by reaction of silicon with HCl gas, containing between 30 and 10.000 ppm 10 chromium, the remaining except for normal impurities being silicon.