OGDENSBURG - Authorities are offering a $25,000 reward for the return of approximately $400,000 in gold pieces that were stolen from a museum in Sussex County.

Sterling Hill Mining Museum co-founder Richard Hauck claims someone entered the museum yesterday and smashed a "hard, resistant plastic" cover.

Hauck says 20 gold pieces extracted from mines around the world were taken. He says if the gold is melted down or altered in any way, it could lose 80 percent of its value.

The nonprofit museum in Ogdensburg showcases the entire mining process through displays and tours of tunnels in an adjacent former zinc mine.