Mine

Function
Mines are installations that extract minerals from system bodies for use by your empire.

Operation
Each mine extracts the racial mining rate per mineral year, modified by the planetary and sector governors mining bonuses and the availability of each mineral.

Formula: (Racial Mining Rate) * (Sector Governor Mining Bonus * 0.25) * (Planetary Governor Mining Bonus) * (Mineral Availability)

Mines require 50,000 population to operate and automatically extract some of each available mineral, placing the results in the colony stockpile.

Automated Mines
Automated mines work just like normal mines except they require no population to operate and are twice as expensive. Standard mines can be automated for a cost of 125% of a standard mine.

Shutting Down
Mines can be mass-shutdown via the Civilian / Ind Status tab of the Economics screen. This will immediately shutdown all manned mining operations. Automated mines do not appear to be able to be shut down. Reactivation requires 6 months.

Misc
For asteroids and comets, an alternative to automated mines is a task group equipped with Asteroid Mining Modules. Especially for distant bodies, the time saved moving the mining ships rather than sending freighters out to move the automated mines might offset the cost of the ships. The downside is that ships have much larger thermal signatures than an automated mining colony, making it easier to find. Of course, the constant stream of mass driver packets is rather visible as well. In either case, having a mass driver on the colony greatly simplifies recovery of the minerals.

For gas giants where mining is impossible, a task group equipped with Sorium Harvesters can automatically convert the otherwise inaccessible Sorium into fuel. While not raw sorium, it's better than nothing.