A mineral deposit is the showing of any type of mineral whether it has value or is just of scientific interest. An ore deposit is a mineral deposit that has an economic value as well as a scientific value.
The copper mineral malachite Photo by Rob Lavinsky |
There are times when you can actually have a very large mineral deposit worth millions of dollars, but because of its location or the cost of production to mineral deposit is not classified as ore. A good example of this is a group of prospectors found a copper deposit in northern Canada that after performing a considerable amount of drilling it was determined that this copper deposit held $100 million worth of copper. Because of its isolated location and the amount of money that would've been required to bring this into production was actually more than the deposit was worth.
This example drives home the difference between ore deposits and mineral deposits to the extent that the prospectors of all eventually called this the $100,000,000. nuisance.