Mine supply for silver is rising faster than for other metals, helped by an increase of by-product from gold-mining operations plus a number of major primary projects in recent years.

FORBES: Thomson Reuters GFMS' Newman: Silver May Move Toward $50 Yet In 2011

Exploration work at a former tin mine in Cornwall may stop because of rising costs concerns, investors say.

BBC: South Crofty tin mine exploration 'could stop'

However, in 2013, Freeport will be gaining access to higher grades of its mine and output is expected to start rising again, the CEO explained.

FORBES: Freeport Copper, Gold Output Falls In 3Q But Expected To Rise Again As Indonesian Production Picks Up

The capacity of mine containing cuprous sulfides and sulfides with disseminated PGMs is rising faster than mines deriving PGMs from nickel-rich sulfide ores, he said.

FORBES: USGS: Sources Of PGMs From South Africa, Russia Likely To Change

Last summer someone in another West Virginia mine punched a hole in an embankment, apparently to keep black water from rising near a piece of equipment needed to continue digging.

FORBES: Magazine Article