September 23, 2011, 4:48 PM ET.

Silver Stages Biggest Drop In 31 Years; Gold Falls Most In 5 Years.

By Murray Coleman

Silver futures kept heading down on Friday, finishing with an 18% fall marking the metal’s biggest drop in decades. Meanwhile, the most active gold contract in New York sank 5.9% to register its largest percentage loss since June 2006.

After the dust settled, gold for December delivery lost $101.90 to finish at $1,639.80 an ounce on the day. For the week, the contract dropped 9.7%.

Meanwhile, silver for December delivery slid by $6.48 to settle at $30.10 an ounce. The day’s sell-off represented the metal’s largest one-day dollar decline since early 1980.

In terms of ETFs (both funds physically storing metals and those buying mining stocks):

The iShares Silver Trust (SLV) dropped by 14.2%.
The SPDR Gold Trust (GLD) slid 5.5%.
The Market Vectors Gold Miners ETF (GDX) lost 4.9%.
The Global X Silver Miners ETF (SIL) fell 7.3%.
The sell-off came amid reports Friday that Greece is preparing for a default and that bondholders would be facing losing 50% on the dollar even in an orderly process. The sell-off followed a move by European officials to pledge to be more flexible to support the region’s bailout efforts and prevent contagion of toxic sovereign debt issues.

Some analysts are pointing to a “counter-trendâ€