Silver mining company shares plunged Monday, in many cases falling more sharply than the broader stock market or the price of silver itself.

The big drop in silver mining shares reflected fears sweeping global markets that sovereign debt problems on both sides of the Atlantic were not being addressed. Failure to make progress heightens the likelihood of recession in Europe, something that could hit silver hard because half its demand comes from industrial customers. 

In the U.S., a Congressional committee failed to agree on $1.3 trillion in cuts to the national debt.

In Europe, Moody's said that recent increases in the interest rates on French bonds could negatively affect the nation's credit rating. Also, the difference between the amount of interest that Italy's and Spain's governments must pay to borrow money for 10 years compared to what Germany must pay for such a loan increased, reflecting the market's lack of confidence in Rome's and Madrid's ability to solve their debt crisis.

The worries lifted the U.S. dollar to a six-week high and hammered the euro.

Silver on the Comex was down 4.1 percent, while U.S. stocks fell: the Dow Jones Industrial Average fell 2 percent, the Nasdaq Composite tumbled 2.2 percent and the S&P 500 dropped 2.1 percent.

The world's biggest silver mining company, Fresnillo Plc, fell seven percent, Endeavour Silver Corp. plunged 7.5 percent,  and Silvercorp Metals Inc. lost 6.8 percent. Hecla Mining Co. dropped five percent, Alexco Resource Corp. declined 5.9 percent and First Majestic Silver Corp. 5.5 percent.

Silver exchange-traded products also fell hard. The iShares Silver Trust was down 3.6 percent, Sprott Physical Silver decreased 4.1 percent and Global X Silver Miners was off 4.6 percent.