December 31,

 

 

    

2016

    

2015

 

 

 

(in thousands)

 

Mineral properties

 

$
9,352

 

$
9,630

 

Exploration properties

 

 
2,518

 

 
2,518

 

Royalty properties

 

 
200

 

 
200

 

Buildings

 

 
4,386

 

 
4,377

 

Mining equipment and machinery

 

 
16,351

 

 
16,998

 

Other furniture and equipment

 

 
952

 

 
841

 

Asset retirement cost

 

 
992

 

 
1,285

 

 

 

 
34,751

 

 
35,849

 

Less: Accumulated depreciation and amortization

 

 
(25,516)

 

 
(24,724)

 

 

 

$
9,235

 

$
11,125