Chapter 16 of 18 · 3955 words · ~20 min read

Part 16

=Antimony and Bismuth.= Antimony is produced in Germany, France, Italy, Hungary, United States, Japan and other countries.

_Bismuth_ comes mainly from Bolivia and Australia. Some is produced in Saxony and England.

_Stibnite_ (antimony sulphide) is the chief ore of antimony. Bismuth occurs in small amounts in a pure state and also combined with sulphur.

These metals form many alloys such as type metal, anti-friction metals, white metal, babbitt metal, fusible metals.

_Tartar emetic_ and other antimony compounds are used in medicine and dyeing.

=Amber= is a fossil resin found chiefly along the shores of the Baltic. It is used in making mouthpieces for pipes, cigar holders, beads and other articles.

=Arsenic.= Germany, England, Canada, the United States and Spain produce the ores. Chemical laboratories transform them into the useful compounds.

_Arsenopyrite_ (arsenic and iron sulphide), orpiment and realgar (sulphides of arsenic) and the sources of arsenic.

_Arsenic_ (white arsenic, arsenious acid or oxide of arsenic), paris green and other compounds and salts are prepared.

Sheep dip, rat poison, insecticides, embalming fluid, pigments and dyes are prepared with arsenic compounds. Arsenic salts are used in preparing certain coal-tar colors.

=Asphaltum= (or mineral pitch) is a bituminous mineral substance found more or less pure, in some localities. The pitch lake of Trinidad and the Bermudez lake at the mouth of the Orinoco in Venezuela, are the largest known deposits of moderately pure asphalt. Smaller deposits of high grade occur in Utah, Cuba and the Barbadoes.

_Rock asphalt_ consists of sandstone or limestone impregnated with asphalt. Much asphalt is produced in refining certain grades of petroleum--such as those obtained in California and Texas.

Rock asphalts are mined in France, Switzerland, Sicily, California, Kentucky and Oklahoma.

For paving rock asphalts are much used in Europe. Trinidad and Venezuelan asphalts are exported in large quantities to the United States and Europe. For paving, these lake asphalts are mixed with broken stone, sand and petroleum residuum.

Pure varieties (gilsonite, marjak, glance pitch) are made into black varnish, used for insulating, etc.

=Barium= is mined in the United States and Germany.

_Barytes_ or barite is a heavy, white mineral (barium sulphate). It is used as a substitute or adulterant for white lead in paints, and in making oxygen.

=Bismuth.= See antimony.

=Building Stones= are quarried for local use in all parts of the world.

_Granite_, _syenite_, _gneiss_, _basalt_ and other hard or durable rocks.

Only stone of exceptional beauty is shipped to a great distance. Scotland, Norway, Massachusetts, Maine and other localities produce fine stones.

=Calcium= has no commercial use in the metallic state. Its compounds, both natural and artificial, are of great economic importance.

_Limestone_ (calcium carbonate) is a very common rock used for building. It may be of almost any color and coarse or fine in texture. It is found and utilized in all parts of the world. In the United States, Pennsylvania, Illinois, Ohio, Indiana, New York and Missouri are the chief producers.

Lime is used in chemical industries and mortar.

_Marble_ is a name applied to limestones suitable for polishing or ornamental work. _Mexican onyx_ is translucent. Fine marbles are quarried in Italy, Egypt, France, Spain and Greece. Vermont, Georgia, Tennessee and New York supply the greater part of the marble used in the United States. Handsome marbles are imported from Carrara, Italy, and other parts of Europe. Mexican onyx is also imported.

Chalk comes mainly from the south of England. We export some Portland cement and import a little from Europe.

_Chalk_ is of peculiar soft texture; _whiting_ is prepared chalk used to make putty and paints; _precipitated chalk_ is similar.

_Lime_ is made by burning (calcining) common limestones. _Portland_ and _hydraulic cements_ are prepared by calcining siliceous limestones or a mixture of limestone and clay. They are of enormous commercial importance, being used in concrete construction work. Europe and the United States produce large quantities. Pennsylvania is the leading state in this industry.

Buildings (both commercial and residences) are now being extensively constructed of cement--in the former case being re-enforced by iron rods.

_Chloride of lime_ (or bleaching powder), _acetate of lime_, _calcium carbide_ and many other compounds are of industrial value.

_Gypsum_ (hydrous calcium sulphate) is used in fertilizers. Plaster is prepared by calcining (burning) gypsum. _Plaster of paris_ is its purest form. _Alabaster_ is compact white gypsum. It is a common mineral mined in many parts of the world. Michigan, Kansas, New York, Ohio and other states produce it. Fertilizers and plaster use up large quantities of this mineral. Plaster of paris is used for casts, decorative plaster work, cement, etc.

_Fluorite_ (calcium fluoride) is a less common mineral. Mined in England, Kentucky and Illinois. It is used in chemical manufacture and as a flux for ores.

_Phosphate rock_ (chiefly calcium phosphate) is important in the preparation of fertilizers, and chemicals containing phosphorus. It is found in deposits of organic origin in South Carolina, Florida, Tennessee, the West Indies, Canada, Spain, France, Germany and England.

The natural phosphates are treated with sulphuric acid as a first step in the manufacture of phosphatic fertilizers. Exported in large amount to Germany, England and other countries.

=Carborundum=, or carbide of silicon, is harder than any known substance but the diamond. Much is manufactured at Niagara Falls, by electrically heating a mixture of coke, sand and salt. It is used for making polishing powder, in grinding wheels, sharpening stones, abrasive cloth, etc.

=Cerium.= See rare metals.

=Chrome= is mined in Asia Minor, Greece, Canada, New Caledonia and California. Its salts are prepared in chemical laboratories.

_Chromite_ (oxide of chromium and iron) is the only ore.

_Bichromate of potash_ is the most important compound. It, together with chromic acid, is used in tanning soft leather. A small percentage added to steel makes it very hard and suitable for burglar-proof safes, tools, etc. Salts of chrome are used for dyes and pigments, such as chrome yellow, chrome green, etc.

=Coal= is one of the most important of all rocks and first among fuels. It consists chiefly of carbon, and is universally regarded as of vegetable origin.

Several theories as to the origin of coal have been put forth from time to time. The one now generally accepted is that the rank and luxuriant vegetation which prevailed during the carboniferous age grew and decayed upon land but slightly raised above the sea; that by slow subsidence this thick layer of vegetable matter sank below the water, and became gradually covered with sand, mud, and other mineral sediment; that then, by some slight upheaval or gradual silting up of the sea bottom, a land surface was once more formed, and covered with a dense mass of plants, which in course of time decayed, sank, and became overlaid with silt and sand as before. At length, thick masses of stratified matter would accumulate, producing great pressure, and this, acting along with chemical changes, would gradually mineralize the vegetable layers into coal.

In passing from wood or peat to coal, the proportion of carbon increases, while that of oxygen and hydrogen decreases, these substances being given off in the form of marsh-gas and carbonic acid gas in the process of decay.