<P> Garnet is another mineral that contains appreciable amounts of hafnium to act as a geochronometer . The high and variable Lu / Hf ratios found in garnet make it useful for dating metamorphic events . </P> <P> Due to its heat resistance and its affinity to oxygen and nitrogen, hafnium is a good scavenger for oxygen and nitrogen in gas - filled and incandescent lamps . Hafnium is also used as the electrode in plasma cutting because of its ability to shed electrons into air . </P> <P> The high energy content of Hf was the concern of a DARPA - funded program in the US . This program determined that the possibility of using a nuclear isomer of hafnium (the above - mentioned Hf) to construct high - yield weapons with X-ray triggering mechanisms--an application of induced gamma emission--was infeasible because of its expense . See Hafnium controversy . </P> <P> Care needs to be taken when machining hafnium because it is pyrophoric--fine particles can spontaneously combust when exposed to air . Compounds that contain this metal are rarely encountered by most people . The pure metal is not considered toxic, but hafnium compounds should be handled as if they were toxic because the ionic forms of metals are normally at greatest risk for toxicity, and limited animal testing has been done for hafnium compounds . </P>

Who doesnt have chemical element named after him