gold mine 
noun
1A place where gold is mined.I remember they were mining material that was higher grade per ton in gold than was at that time mined from the Pamour gold mine in Timmins, Ontario....
- Anglo's Mponeng gold mine is the second-deepest mine in the world.
- Most people don't realize that Poppy Bush had a gold mine: Barrick Gold Mining Corp.
1.1A source of wealth, valuable information, or resources: the book is a gold mine of sporting trivia...
- The book is a gold mine of information, learned by McMoneagle over two decades of hands-on training, research, and applications.
- The Internet has proved to be a gold mine of information for people researching their family history.
- I suffer from paranoid schizophrenia and depression and find the net a gold mine of information.
Derivatives
gold miner
- South Africa's AngloGold has offered 26 shares for every hundred Ashanti shares, a takeover which could make it the world's top gold miner.
- The story there goes that Russian Jack, a gold miner in the Halls Creek rush, helped a mate with two broken legs, by pushing him in a barrow 300 kilometres to medical help.
- Meanwhile, Dundee Precious Metals has decided to convert itself from an investment company to an operating gold miner, Goodman announced on Tuesday.
gold-mining
/ noun & adjective ...- In the first three-quarters of 2005, the world's gold-mining companies are estimated to have produced only 1% more than in the same period of 2004.
- As recently as Christmas Eve, Thistle Mining, the Scottish-Canadian gold-mining firm he chaired, confirmed that its executive office in Edinburgh was to close.
- But the US Treasury has been urged to oppose the idea by gold-mining firms who fear that a sell-off could depress global prices for the metal.