LOL YOU GUYS ARE AWESOME!!!
Thats the movie.
Here is a link I found.
http://www.badmovies.org/movies/laserblast/
Like I said I saw this movie when I was about 10 back in the late 70's early 80's. LOL somewhere around there. It scared the crap out of me. I remeber watching it on TV. I also remember the big hand grenade like necklace too. I'll have to buy it now on DVD.
THANKS!!!!