Siliceous Schistus, Hone-Stone, or Novaculite
- Novaculite. Kirw. 1. 238.
- Whet Slate. James. 1. 331.
- Argile schisteuse novaculaire. Haüy, 4. 448.
Hone-Stone is generally considered as a foreign substance, said to be imported from Turkey; and has heretofore been always mentioned by authors as such. I can only say that we have a substance so nearly resembling it in England; that it may very fairly be considered as the same; and therefore I esteem the Hone a product of our own country. It is more or less an attendant upon Slate, Its colour is grey, light greenish grey, buff, and nearly white; its fracture splintery. I have it from the Carnarvonshire hills, North Wales, (see the upper specimen) of a cream-colour, like what is usually called Turkey Hone. Such is much esteemed by the cutlers at Sheffield, and is sold in proportion to its quality. A piece of about six inches in length, fit for sharpening a razor, was thought so excellent as to be worth a guinea. Many varieties of Hone-Stone are found near Conistone, in Lancashire, and are sometimes so prettily marked with dendrites as to have gained the appellation of Mocoa Stones*. The greenish Whetstone with small dendrites, from thence, is figured behind, and the upper middle figure is one with the larger dendrites; this nearly resembles the darker Turkey Hone, or, which is much the same, the Carpenter’s Oil-stone, but is more stained and blotched. It is, of course, sometimes found without the dendrites; but I figure it thus, to give one of its characters, and to exhibit a specimen, of the sort of dendrites which are supposed to be Manganese, and are sometimes like stains upon the surface, as in the middle figure, and sometimes run through the Stone in great variety, as in the back figure. Chorley Forest, in Lancashire, produces a variety of Hones, or stones fit for sharpening tools, which are called Chorley Hones. Indeed, there are vast varieties of stones used by the cutlers, according to the coarseness or fineness of the grain; and their distinctions are all so essential, that it becomes of much consequence to know the sorts for different uses, and the trade in them is of great importance both abroad and at home.
It is perhaps worthy of remark, that these stones may be scraped with a knife, and give, generally, a light streak like that of common Slate, although they will grind the hard steel that will cut or scrape them. Schistose rocks of many different compositions resemble wood. Perhaps, from some of those usually called Turkey Hones resembling wood, they have been thought to be petrified wood. I am possessed of Schistose Rock from Devonshire, which has been called Rotten-wood rock, from its resemblance to rotten wood. I have, however, some petrified wood that would nearly answer the purpose of a Hone, from Somersetshire, which shows the lateral fibre very distinctly, splitting with the usual longitudinal grain of the wood, and has a slaty aspect.
- * Mocoa stones from Germany are perhaps coloured by Bitumen, but those from the East Indies by Manganese. In the first, the dendrites are apt, to wear out, in the latter they art durable.