Soapstone, or Soaprock Steatite Enlarge
July 1. 1807. Publish’d by Ja.s Sowerby. London.
British Mineralogy
CCXXII
Silex steatites

Soapstone, or Soaprock Steatite

  • Class 2. Earths.
  • Order 1. Homogeneous.
  • Gen. 4. Silex.
  • Spec. 13. Steatites.
  • Div. 3. Amorphous.

Steatite, commonly called Soaprock, is found in Norway and China, as also at Portsoy in Scotland, and at the Lizard Point in Cornwall. It is found of a fine waxy white like white hard soap or Windsor soap, and feels so similar to the touch as naturally to assume that name. It is occasionally coloured yellow, often so as to resemble common yellow bee’s wax; it is also occasionally dendritically coloured with Iron Ochre or Manganese, from light yellow, light gray, Sec. to red or crimson, as figured. The whitest is of course preferred in Porcelain, for which it is often used. It is found of various degrees of hardness, from such as is easily scraped by the fingernail to such as can scarcely be scratched by a pin. It, however, hardens in the fire, according to the time of exposure, until it will scratch glass like Quartz; the more transparent becomes opaque, and if polished before putting into the lire will retain the polish after heating. The coloured varieties are affected by heat according to what the colouring matter may be, I suspect that this may be the Hoa-che of the Chinese, which has superseded the Kaolin; but so far as I have seen they do not understand it so well, although the china made from it is said to be better in some respects, I believe it is better understood in England. It may be chosen so as to be cut easily into any form, and the Chinese use some varieties for carving figures and very delicate fret-work . The softest might serve this purpose as well as the hardest sorts, and either might be hardened afterwards by heat.

The upper kind comes from the Lizard Point in Cornwall, and is found in veins in the Serpentine Rock. The lower piece is extraordinary for the strata of colours, which perhaps are as vivid, and distinct, as will ever be found in this substance. I have another specimen, by favour of my friend the Rev. H. Davies, with Magnetic Iron in it in a small quantity.

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