1. A three-dimensional network of thin sheets of mineral projecting from a cave wall. The boxwork is vein fillings etched from the cave wall by dissolution of the host limestone and consists mostly of calcite and quartz. It is not common, but spectacular displays occur in Ind Cave, South Dakota, USA [9]. 2. Network of thin blades of calcite or gypsum etched out in relief on the limestone walls and ceiling of a cave [10].