Should I Turn In My Savings Bonds An Invest In Something Else?

I don’t know a lot about economics but I have questions.
Well, I have been fortunate enough to have very generous grandparents who fund my college. I have about 100k left in savings bonds for college. (This is the actual value they are at now.)They are mostly 5 or 10k savings bonds. Some have matured and are growing at a rate of 3 or 4 percent (they were taken out when I was a child and the economy was better then which is why the mature rate is this high or whatever.) I decided to go to a cheaper school, so… I will not nearly need all this money. When I cash in these savings bonds, the government is going to tax me to hell because they are not being spent on education (as they remain untaxed if they are going towards a university as a full-time student.)
I am wondering if I should take them out now and invest in something like gold or silver or anything that will grow faster than these bonds but not with too much risk. Something that I wont be taxed so much for. Or should I just it in the form of bonds to be safer?
I know I am truly blessed to have this opportunity. Thanks.