This extraordinary mineral is found embedded in sandy loam, in alluvial soil ([269]), and occurs in various parts both of Europe and Asia. It has been found in ferruginous sand, near Woburn, in Bedfordshire, and near Nutfield, in Surrey. Immense pieces of it are discovered in some places in the original shape of the trees; trunks, branches, and roots. In the year 1752 the whole under part of the trunk of a tree, with its branches and roots, was found, in a state of woodstone, near Chemnitz, in Saxony; and, in the Electoral Cabinet at Dresden, there is part of the trunk of a tree, from the same place, which measures five feet in length and as many in thickness.
Woodstone is in considerable request by lapidaries. It takes a good polish, and is made into beads for necklaces, and other female ornaments. In the East Indies it is generally called Petrified Tamarind Tree.
88. COMMON SAND is a granulated kind of quartz; or consists of rounded grains of small size, which have a vitreous or glassy surface.
It is usually of white or yellowish colour; but is sometimes blue, violet, or black.
In the torrid regions of Africa and Asia there are immense tracts of desert covered only with sand, so dry and light as to be moveable before the wind, and to be formed into vast hills and boundless plains. These are incessantly changing their place, and frequently overwhelm and destroy the travellers whose necessities require them to enter these dreary realms.
Sand has numerous uses. When mixed in due proportion with lime, it forms that hard and valuable cement called mortar. Melted with soda ([200]) and potash ([205]) it is formed into glass; white sand being used for the finer kinds, and coarse and more impure sand for bottle glass. A very pure kind of sand which is found in Alum Bay, on the west side of the Isle of Wight, and on some parts of the coasts of Norfolk, is in great request by glass-makers. Sand is also employed in the manufacture of earthenware; and its utility in various branches of domestic economy, but particularly for the scouring and cleaning of kitchen utensils, is well known. In agriculture sand is used by way of manure, to all soils of clayey lands: as it renders the soil more loose and open than it would otherwise be. The best sand for this purpose is that which is washed by rains from roads or hills, or that which is taken from the beds of rivers.
There is a kind of sand which is naturally mixed with clay, and has the name of Founder’s Sand, from its being chiefly employed in the formation of moulds to cast metals in. At Neuilly, in France, there is a bed of perfectly transparent and crystalline sand. Each grain, when examined with a magnifying glass, is seen to consist of a perfect six-sided prism, terminated by two six-sided pyramids.
The uses of the different kinds of Sandstone will be enumerated in the account of the rocks (267, 268).
89. LYDIAN STONE is a kind of flinty-slate, of greyish or velvet-black colour, not quite so hard as flint, opaque, and about twice and a half as heavy as water.
It is usually massive, and, internally, has a glimmering appearance.