Unless the context in which used clearly requires a different meaning as used in this article:
(a) "Open-pit mine" means an excavation worked from the surface and open to daylight.
(b) "Underground mine" means subterranean workings for the purpose of obtaining a desired material or materials.
(c) "Sand" means waterworn sandstone fragments transported and deposited by water.
(d) "Gravel" means an occurrence of waterworn pebbles.
(e) "Sandstone" means a compacted or cemented sediment composed chiefly of quartz grains.
(f) "Limestone" means a sedimentary rock composed mostly of calcium carbonate.
(g) "Clay" means a natural material of mostly small fragments of hydrous aluminum silicates and possessing plastic properties.
(h) "Shale" means a laminated sedimentary rock composed chiefly of small particles of a clay grade.
(i) "Iron ore" means a mineral or minerals, and gangue which when treated will yield iron at a profit.
(j) "Manganese ore" means a metalliferous mineral which when treated will yield manganese at a profit.