Gallery
Historic Ores

Last update: 4 December 2016

This gallery displays a selection of ores, i.e. rock and mineral specimens of economical interest, as well as mining memorabilia. They are arranged by chemical element. As of March 2016, elements considered are aluminium, beryllium, carbon, copper, iron and tin. All rock and mineral specimens were deaccessioned from collections of historical importance.

WANTED: Bergbauflaschen, handsteine, antique ingots


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Metals

Aluminium
From bauxite

Bauxite drill core section from Arkansas formerly from the Frank L. Hess (1871-1955) and Arthur L. Flagg (1883-1961) collections.

The rarest and most precious metal until the late 19th century

Aluminium is the most abundant metal and the third most abundant element in the Earth's crust after silicon and oxygen. Yet, native aluminium is extremly rare and extraction from ores was very expensive prior to the late 19th century, making aluminium more precious than gold and platinum. In contrast, aluminium coins were made in the early twentieth century as a cheap replacement to other metals [1]! Bauxite, the principal aluminium ore, was first discovered by chemist Pierre Berthier in 1821 while investigating specimens found near Les Beaux in southern France. The name bauxite was proposed in 1861. The commercial production of aluminium became possible at the end of the 19th century thanks to the Bayer process. Karl Joseph Bayer, an Austrian chemist, invented in 1887 the technique to separate aluminium oxide (also known as alumina, Al2O3) from the iron oxide in bauxite. Sir Humphry Davy, the British chemist credited with giving aluminium its name, tried unsuccessfully to produce the element by electrolysis in the early 1800's. It was finally Charles Martin Hall in the U.S. and Paul L. T. Heroult in France, who discovered independently in 1886 that it was possible by passing a direct current through a solution of alumina dissolved in molten cryolite (sodium aluminum fluoride, Na3AlF6) (i.e. Hall–Héroult process). Until 1987, cryolite was mined from deposits found on the west coast of Greenland [2]. Today, chemists synthesize the compound from fluorite, which is much more common. Hall received a patent for the process in 1889, one year after he founded the Pittsburgh Reduction Company, which would later become the Aluminum Company of America (Alcoa). In the United States, Arkansas was a major supplier of bauxite around World War II [3]. Nowadays it is predominantly mined in Australia, Africa, South America and the Caribbean.

Figures: [1] Notgeld coins (Wattenscheid Stadt, 1920) | [2] Cryolite, Greenland (GRMI spe. coll.) | [3] Bauxite core, Arkansas (F.L. Hess / A.L. Flagg)

WANTED: 19th / early 20th century aluminium ingot

Copper
From native copper

Copper crystals in a pocket found in Central Mine, Keweenaw Co., Michigan, and formerly from the Colorado School of Mines (purchase from E. M. Gunnell in 1949).

The first metal worked by Man

Curious lumps of native copper have always fascinated. Metalworking defined the transition from the Stone Age to the Bronze Age (which also includes the early Copper Age). Ancient civilizations rapidly found supplies of copper, such as the Sumerians and the Egyptians. Bronze was made by mixing copper ore with tin ore. The Egyptians used the "Ankh" sign for copper while the ancient Greeks named it "Chalkos". The term copper appeared as the anglicized version of "cuprum", a word corrupted from the Latin sentence "aes Cyprium" (indicating that Cyprus was an important source of copper in the Early Christian Era). To be continued.

Figures (Michigan suite): [1] Copper crystals, Central Mine (E.M. Gunnel / CSM) | [2] Commemorative coin, Houghton (MCMT) | [3] Arrowhead (?), Drayton Plains ("Grandpa Walker's property")

Figures (Cornwall suite): [4] Coin clump, Cornwall (Admiral Gardner shipwreck)

Tin
From cassiterite and stannite

Tin bar from Cerro de Los Remedios, Durango, Mexico - formerly from the Arthur L. Flagg (1883-1961) collection.

From the mythical Cassiterides to the modern world

Text coming later.

Figures: [1] Stannite, Cornwall (J. Neeld) | [2] Tin, lab. sample (A.L. Flagg) | [3] Wood tin, Durango (A.L. Flagg) | [4] Tin bar, Durango (A.L. Flagg)

WANTED: Cornwall Cassiterite from antique British collection.

Other chemical elements

Beryllium
From beryl and bertrandite

beryllium beryl Behier

Madagascar beryl crystal from the Jean Béhier (1903-1963) collection.

The lightest alkaline earth metal

Beryllium improves many physical properties of metals when added as an alloying element, in particular to copper. It is especially useful in the aerospace industry. Louis-Nicolas Vauquelin (1763-1829) discovered beryllium in 1798 while Friedrich Wöhler (1800-1882) coined the name "beryllium" when he isolated the element in 1828. The two main ores of beryllium are beryl [1] and bertrandite. Beryl was the main ore of beryllium prior to 1969. The mining of bertrandite at Spor Mountain, Utah, supplies nowadays most of the world’s beryllium due to the reduced cost of extraction.

Figures: [1] Beryl, Madagascar (J. Béhier)

WANTED: Bertrandite specimen (Spor Mountain, Utah) with documentation from the late 1960's.

Fuels