Shoad Tin and Gravel Stones* Enlarge
Dec 1 1809 publishd by Js Sowerby London.
British Mineralogy
CCCXXXVIII

Shoad Tin and Gravel Stones*

The upper figure came probably out of a large vein of Tin, and is what the Cornish miners call Shoad Tin. It occurs in the neighbourhood of the primitive formation among alluvial deposits from it. It is much the same as that in the veins, composed of more or less confused masses of Crystals, These, and even the perfect Crystals, are often found worn into pebbles in the streams, and are termed Stream Tin, resembling common Flint Pebbles, or Gravel Stones They are of different colours, as here figured, and may best be known in the first instance by their superior and extraordinary weight in the hand. They are also called Grain Tin when in grains or very small portions.

The streams are often conducted with much attention over chasms and small valleys to the lower grounds, where means are contrived, by washing, to collect large quantities, separate from the mud and other matters, and equal to that obtained by mining. There is moreover less trouble in the separating and breaking for smelting.

  • * Reproduction note: This illustration did not have a title so the title was derived from the names in the description.
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