Bunny: fluffy pet or surprise ore deposit

To most people, a bunny is a small furry mammal with long ears and a cotton tail, the sort of creature children keep as pets or hunt in spring meadows. The word itself comes from the old English term for rabbit, and has been cuddled into our vocabulary as a term of endearment.

In mining and extraction, a bunny is something entirely different: a sudden, irregular enlargement of ore within a rock face. Where a vein or lode represents a consistent seam of mineral running predictably through the host rock, a bunny is an unexpected mass or pocket of ore that swells out from the main body. Think of it as a bulge in the rock that concentrates valuable mineral in one place. Miners prize these pockets because a bunny may yield more ore per unit of rock broken than the vein feeding it.

The term is most common in hard rock mining: precious metals, base metals, and gemstone work. A prospector or development miner might break into a new section and suddenly encounter a bunny of copper or gold, a localized concentration that justifies the labor of the surrounding waste rock. The bunny is distinct from other geological features like stringers (thin parallel veins) or horses (blocks of country rock trapped in ore) because it is defined purely by its sudden, bulbous enlargement of the ore body itself.

Why the name? The leap is metaphorical. A bunny appears suddenly and unexpectedly in a field, just as a bunny of ore appears without clear warning in the rock face. The term treats the geological accident as a kind of pleasant surprise, the way a prospector or miner might treat stumbling upon a pocket of high-grade material. It is a folk term, not a formal geological one, and carries the informality and optimism of the mining camp.