Avengers is actually right. the best flutes are sterling silver, or sometimes platinum. I have never heard a solid gold flute (they do exist they apparently have quite a warm tone) but I've played a few gold plated silver ones.
Your typical everyday flute would be nickel silver.
http://iwk.mdw.ac.at/Forschung/english/lin...linortner_e.htm
Silver is a wee bit harder than gold by the way.
Why is everyone forgetting that steel is incredibly resonant? Tuning forks anyone? My bike frame has a lovely ringing tone!