a source of great wealth or profit, or any desirable thing.
3.
a copious source or reserve of something required:
a gold mine of information about antiques.
Origin
1425-75;late Middle English
Examples from the web for gold mine
If hydrogen fuel cells are the power source of the future, pee is a potential gold mine.
In the short term, this is a potential gold mine for foreign-affairs scholarship.
At the same time, the company also digs into a gold mine unique to this picturesque city.
The current crisis in the retail business has made his work a gold mine.
Cell phone companies are finding that they're sitting on a gold mine--in the form of the call records of their subscribers.
If shopping was an emotional minefield, then strategic marketing could be a gold mine for companies.
The complex, the world's largest combined copper and gold mine, is enormously profitable.
Both properties are run by the same owner, who is a gold mine of information.
And so it was a gold mine for private military contractors that needed training grounds.
Booming development and hurricanes regularly wiping out beaches are eroding several feet of the sandy gold mine each year.
British Dictionary definitions for gold mine
gold mine
noun
1.
a place where gold ore is mined
2.
a source of great wealth, profit, etc
Derived Forms
gold-miner, noun gold-mining, noun
Idioms and Phrases with gold mine
gold mine
A rich, plentiful source of wealth or some other desirable thing, as in That business proved to be a gold mine, or She's a gold mine of information about the industry. [ First half of 1800s ]