Silver mining companies suffered acute losses Friday, with many posting double-digit drops in their share prices.

Silver itself closed down 17.7 percent Friday -- its biggest daily percentage drop in nearly two decades -- and was 25 percent below its Wednesday closing price.

Among the hardest hit silver companies Friday in late afternoon trading were Silver Wheaton Corp., down 10.18 percent, Endeavour Silver Corp., down 11.06 percent, Fortuna Silver Mines Inc., down 10.18 percent, and Great Panther Silver Ltd., down 10.46 percent.

Exchange-traded funds backed by silver were similarly hurt by the downdraft. Sprott Physical Silver plunged 16.52 and iShares Silver Trust dropped 14.35 percent.

With China's economy slowing, with our economy going into a recession, with Europe going out the window, the industrial metals are being sold off viciously and silver is caught up in that, Frank McGhee, head precious metals dealer at Integrated Brokerage Services in Chicago, told the Wall Street Journal.