Page:Transactions of the Geological Society, 1st series, vol. 2.djvu/128

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Mr. William Phillips on the Veins of Cornwall.

is often termed a sparry load. Quartz is sometimes called hard spar by the Cornish miner, and fluate of lime, sugary spar.

If iron pyrites abound, the load is said to be mundicky, and when this occurs at a shallow level it is not always unpromising: even if it continue in depth, and be somewhat compact, particularly if mingled with portions of yellow copper ore, there are many instances of such veins proving rich beneath. No distinction is made by the miner between iron pyrites and arsenical pyrites. The latter is however rarely very abundant.

A vein that contains a great proportion of chlorite is termed a peachy load: it promises for tin rather than copper, which is rarely accompanied by chlorite. Tin was found in it, in Pednandrae, Polgooth, Relistian, Huel Unity, and in many other mines. I have specimens of the yellow copper ore in chlorite from Relistian and from the Wherry mine, the workings of which were under the sea in Mounts' Bay.

A vein is said to be flucany when either one or both its sides, or walls, are lined with a whitish or bluish clayey substance, or when this substance is interspersed through the vein itself. Flucan in some few instances has abounded so greatly, that it has been difficult to prevent its running in upon the miner in working the mine. This was the case in the early working of the productive copper mine called Huel Alfred, as is noticed in the annexed description of some of its veins.

When tin ore is intimately mingled with quartz and chlorite, the vein is termed a scovan load, which is of a dark brown or of a greenish hue, but not very hard, or compact. A load of this description rarely exceeds 12 or 14 inches in width, but it sometimes occurs in a vein the contents of which are not solid, thence by the miners termed a sucked stone. A load so circumstanced is often several feet wide.