This material comprises the bulk of a mineralized vein, consisting of gangue minerals like quartz, calcite, or fluorite that surround the valuable metallic ores. Miners must extract and process this material to get to the pay dirt, eventually discarding it as waste during the milling process.
Heard on the job
The heading is full of barren veinstuff right now, but the geologist insists the gold will pick up in another ten feet.