This term describes a mine that has run out of paying ore, leaving only barren rock. Originating from historic Spanish mining law and adopted widely in the Americas, it represents the exact opposite of a bonanza. When a vein pinches out or the grade drops below the economic cutoff, the operation is declared a borrasca and typically abandoned.
Heard on the job
We chased that quartz vein for three months before admitting the whole drift was a borrasca.
Insider tip
Miners use this word both for the physical barren rock and the financial ruin that follows it.