What to mine on Capsuleers.app takes the Survey Scanner output copied from the client and ranks the belt's rocks by ISK per m³. For each ore type it works out whether it pays more sold compressed or reprocessed into minerals, shows how many rocks there are, the belt's volume and value, and tells you which rock to start from.
Enter your ship's mining yield in m³ per minute and you also get ISK per hour and the time to clear the rocks. You can add an ore by hand that is not in the scanner to compare it.