The Revett-owned silver and copper mine located just outside Troy that closed Dec. 1 because of falling rock, will not open this week as hoped.

Revett CEO John Shanahan said underground activity at the mine will not resume this week and perhaps not next week either.

A release from Revett on Monday states “at this stage, we believe it may take up to two weeks to assess, monitor and return to full operations.”

Also, on Monday, Revett stock lost 10 percent of its value.

As a result of geotechnical consultants’ tour of the mine and recommendation by the Mine Safety and Health Administration (MSHA), the mine will be installing geophone monitoring devices, and when that is complete, mining operations will resume as soon as possible. 

Shanahan said officials are concerned about continued rock movement in the mine and have decided to take more time before allowing work underground to resume.

“We’re playing this as safely as we can,” Shanahan said Friday. “For safety’s sake, we’re going to be wearing both a belt and suspenders.”

Asked whether he expected ore extraction to be finished for the year, Shanahan said that is not necessarily the case.

“It might be another week or week and a half, but I don’t think we’re done for the year,” he said.

Underground work was halted Saturday, Dec. 1, when Vice President of Operations Doug Miller called off operations because of the falling rock.

Miller said there are about 95 miles of tunnels in the mine, of which about 10 percent are actively mined.

Unrelated to the stoppage, Miller said, was a 2.9-magnitude earthquake four days later on Dec. 5.

The U.S. Geological Survey reported the quake at 3:41 a.m. Dec. 5 with an epicenter 35 kilometers (21 miles) southwest of Libby. 

The Revett mine employs 205 people, about half of whom work underground.