Mineralogy
3 of the 6 encyclopedias on this shelf carry an entry for Mineralogy. All 3 are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
the study of minerals. It discusses crystals and the laws of their formation. The physical properties of minerals are investigated with reference to light, heat, and electricity. Hardness, tenacity, elasticity, cleavage, and fracture are discussed, as well as taste, odor, and touch. Alum, for instance, has an astringent taste; saltpeter, a cooling taste; sulphuric acid is sour; zinc sulphate, metallic in taste. Arsenical iron has the odor of garlic; roasted selenium smells like horseradish. Certain varieties of limestone give off the odor of rotten eggs when rubbed, etc. Talc feels greasy; genuine gems feel cold; glass feels warm. The mineralogist classifies rocks also with reference to their original structure, composition, crystalline character, etc. Over a thousand minerals have received names. See Granite ; Marble ; Diamond ; Hardness , etc. Mineral Products of the United States . In 1909 the Conservation Commission made a report on the mineral products and resources of the country, embodying valuable statistics. According to this report, the total output for 1907 exceeded $2,000,000,000. The chief mineral products were: Soft coal, tons ..... 395,000,000 Hard coal, tons ..... 85,000,000 Petroleum, barrels ..... 166,000,000 Iron ore, high grade, tons ..... 45,000,000 Iron ore, low grade, tons ..... 45,000,000 Phosphate rock, tons ..... 2,500,000 Copper, pounds ..... 896,000,000 Clay products, value ..... $162,000,000 Stone ..... $71,000,000 Cement ..... $56,000,000 Natural gas ..... $50,000,000 Gold ..... $90,000,000 Silver ..... $37,000,000 Lead ..... $39,000,000 Zinc ..... $26,000,000 In the same report the committee estimated the known supply of American coal at 1,400,000,000,000 tons, enough to last 150 years at present rate of consumption; high grade iron ore, 3,840,000,000 tons, enough for 50 years; petroleum, 20,000,000,000 barrels, sufficient for 50 years. Many are becoming alarmed lest our supply of useful minerals be exhausted. From a chemical point of view, it is true that not an atom of any mineral can be annihilated or destroyed, but it is none the less probable that once the mineral atoms that have accumulated in the earth during geologic ages have been scattered, not all the ingenuity of man can gather them together again. It is quite possible that aluminum, as plentiful as clay, and sunshine, the gift of the sun, may take the place of iron and coal; but none the less it behooves a thoughtful people to be frugal in the use of nature's bounties. See Coal ; Iron ; Gas ; Copper ; Gold
Collier's New Encyclopedia (1921)
in natural history, a science treating of those natural inorganic products of the earth which possess definite physical and chemical characters. In 1669 Nicolas Steno, a Dane, made the discovery that in crystals of quartz the angles of inclination of adjoining faces were constant, and that the number of faces and their grouping, notwithstanding variations in size, were always the same. In this year also the doubly-refracting property of Iceland spar was observed. In 1772 Romé de l'Isle announced that the various shapes of crystals of the same product were intimately related. The Abbé Haüy in 1784 discovered that 10 forms, including six of de l'Isle, could be produced from various minerals by cleavage, and that these must be the true primitive forms. Professor Weiss, of Berlin (1809-1815), established fundamental lines, which he called axes, and to which he showed how all the primitive forms and secondary planes were related. Subsequently, though independently, Mohs (1820-1825) arrived at a division of crystals into four systems of crystallization which coincided with the four axial groups of Weiss. He also announced two other systems of crystallization, in consequence of more precise measurements being obtainable by the use of the reflective goniometer. The discovery by Malus in 1808 that a ray of ordinary light reflected at a certain angle from a glass plate possessed the same properties as that which emerged from Iceland spar, enabled Brewster in 1819 to point out the intimate relation which existed between the cleavage form of a mineral and its action on light. The early attempts at classification were very vague, and were founded on supposed external differences, being divided into Earths, Stones, and Metals. Cronstedt's "Essay" (1758) was the first foreshadowing of a principle in a system of classification. The earths he classed as Calcareous, Siliceous, Argillaceous, and so on. Werner's last system divided fossils (as minerals were then called) into four classes: viz., Earthy, Saline, Combustible, and Metallic. The system of Haüy (1801), like that of Werner, was a mixed one, but it was the first to direct attention to the importance of crystallographic form to a system of classification.
The Encyclopedia of Founding (1892)
The science which treats of the solid and inanimate materials of which our globe consists, the four classes of which are earthy minerals, composing the greater part of the earth's crust; saline minerals, inflammable minerals, and metallic minerals. See MINERALS; METALS; EARTHS.
What Has Changed in the Last Century
Aiton's 1910 entry has the mineralogist tasting alum for astringency and sniffing arsenical iron for garlic, and reports that "over a thousand minerals have received names"; the International Mineralogical Association's list now runs past 6,000 species, with roughly a hundred new ones approved each year. The decisive break came just after these accounts: Max von Laue's X-ray diffraction experiment of 1912 and the work of W. H. and W. L. Bragg from 1913 let mineralogists read atomic arrangements directly, so the crystallography traced by Collier's from Steno through Haüy and Weiss was superseded by structure determination, later joined by the electron microprobe. Classification also shifted decisively from the old "Earthy, Saline, Combustible, Metallic" divisions to chemical schemes based on anion groups, as in the Dana and Strunz systems. Aiton's warning that American petroleum, estimated at 20 billion barrels, would last 50 years proved far too gloomy, though its wider plea for frugality reads very modern; mineralogy has meanwhile extended off the planet, with new minerals named from the Apollo lunar samples.
Written for this edition, 2026.