Most volatile mining stocks

Does anyone know what are the most volatile Gold mining stocks, and how you'd find out?

 

Some good ones:

AEM
AU
GOLD
NEM
SSRI
PAAS
IVN
LIHR
ABX
GFI
GG

 

FCX
RTP

RTP -The Company’s business is finding, mining and processing mineral resources. Its major products include aluminum, copper, diamonds, energy products, gold, industrial minerals (borates, titanium dioxide, salt and talc), and iron ore