1. To extract a specific material, such as ore or minerals, through digging and boring. They used to mine for silver on this part of the mountain. We've been mining for coal in this region for centuries—if that ends now, our entire community will be destroyed.

2. To dig and bore into a particular thing or location in order to extract a specific material, such as ore or minerals. In this usage, a noun or pronoun can be used between "mine" and "for." They've been mining these hills for diamonds for so long that the whole area is stripped bare. We're going to mine this section of the mountain for a rare metal used in electronics.

3. To obtain a lot of very detailed information from someone or something. In this usage, a noun or pronoun can be used between "mine" and "for." This book has been a great resource to mine for facts about the Civil War. My neighbor used to be an astronaut, so I've been mining him for information to use in my science project about the solar system.