Honestly, I hate the propick so I followed Flexible Games Mod tutorials and basically ripped his rock sniffer to be a metal detector. I highly suggest if you want to get into VS modding to follow his guide as it was a god send! Keep in mind some of the steps has changed, but its a great starting point.

Build with a prospecting head, two resin, and two sticks. Hit a rock block to check if it has ore underneath. You will get an alert in the chat window, if it does it will break the block, if it doesnt the block will stay.

Im not going to change this or add to it as it was my first mod and it works