TRIPOLI, according to Phillips, is an earth of a grey yellow or red colour, used in polishing, that was first introduced from Tripoli in Africa, whence its name, but it is found in France and elsewhere, and is said to contain nearly 90 per cent. of silex.
2. Red Tripoli has been largely prepared from a brick earth found near Battle in Sussex. When burned in lumps it is nearly as heavy as emery stone, after which it is ground and sifted, and presents the appearance of crocus, but is coarser and is used for similar but inferior purposes.
A Red Tripoli prepared by calcining and pulverising Clunch or Curl Stone, found in the coal and iron districts of Staffordshire, etc. is highly recommended by Mr. Gill. See the articles on the Oxides of Iron.
3. Yellow Tripoli, sometimes called French Tripoli, is employed for polishing generally, and amongst other substances for light-coloured hardwoods that would be stained by the absorption of darker powders into then* pores. A large quantity of fine yellow tripoli was obtained in digging the canal in the Regent's Park, London; some additional particulars are given on this