i am now almost 79 only another month and day. and also teach faceting to anyone interested for free. i now have 54 yrs of experience faceting and what i said above is on going. if you go to facebook and type in ultra tec search i have a video put there by ultra tec of a stone i cut an you can see what i do. by the way i just want to let everyone know i found diamond powder 50,000 grit from glass polishers dealer on ebay in china for $80 for 1000 carats and it goes a long ways. all my students and i use it and polish very quickly, its a very good quality. thats only 8 cents a carat. and the stone on facebook is a neodymium yttrium aluminum garnet– laser YAG– and is 245 cts. 193 facets.