In the very early days of quartz mining, crushing machines were relatively light, and kilns were used to roast quartz, to soften it prior to crushing. The quartz was added to the kilns, of variable construction, in layers, interspersed with layers of fuel. The quartz was roasted as the fire worked upwards, and the product was shovelled out from below. Their use continued in some areas such as Maldon which had high mineral content in the ore.