THE GOLD

Gold During the Middle Ages

Albert's view of the origin of placer gold was challenged by Biringuccio in his Pirotechnia, written in 1540, and by Agricola in his De re metallica, published in 1546.
Vincentius Bellovacensis (Vincent de Beauvais), French Dominican, compiled an immense encyclopedia, the Speculum Majus, of which one part of three, the Speculum naturale, in 32 books and 3,718 chapters, is a summary of the natural history known to the western Europeans at the middle of the thirteenth century. In this great work, Vincent discusses geology and mineralogy, mostly following the thought of Avicenna and Albertus Magnus (his contemporary). Vincent believed in the alchemical sulphur-mercury theory of the constitution of metals, in the transmutation of metals, and in other alchemical doctrines about the natural upgrading of base metals with time, to yield silver and ultimately gold, as the most noble of all metals, shown by the following statements (see Needham, 1959, p. 639).
"Gold is produced in the earth with the aid of strong solar heat, by a brilliant mercury mixed with a clear and red sulphur, digested and ripened for more than a hundred years.... White mercury, fixed by the virtue of incombustible white sulphur, engenders in mines a matter which fusion changes to silver... Tin is generated by clear mercury and white and clear sulphur, digested and ripened for a short time subterraneously. If the digestion and ripening process is very prolonged, it becomes silver."

The general theory as enunciated by the later alchemists is best stated in the words of Aurelio Augurelli (1454-1537), alchemist of Venice, as freely translated from Vellum aureum et chrysopoeia, published in Venice in 1515, as follows:
"The origin of the metals is the centre of the earth ... penetrated by the sun's rays and by other celestial rays which ripen and mature the assembled vapours that then pass upward and fill fractures in the crustal rocks. Where the vapours are condensed and cannot move farther they solidify into those unripe metals that fill veins in the earth's crust.... Finally with time Nature transforms these metals into gold, silver, copper, and so on...."

Some of the later alchemists thought that mineral veins were offshoots of a giant treelike body rooted deep within the earth. The mineral veins were considered to be the branches of this great tree, and the metals were supposed to have risen like sap. The treelike body was represented as growing under the stimulus or influence of some celestial body (in the case of gold, the sun), and base metals such as lead and copper were constantly being transmutated into the noble metals. This belief in the transmutation and growth of metals within the earth's crust was widespread in Europe in medieval times and had many fanciful modifications. One of these implied that the minerals and metals were male and female and produced seeds (the petrific and metalline seeds) by which they reproduced themselves.

Many interesting accounts of the spontaneous generation and growth of metals, particularly gold, in the earth's crust were extant in the late middle Ages and were carried into the literature of the sixteenth to eighteenth centuries. Several alchemists describe how sprigs and dendrites of gold grow among the vines of Hungary and Romania. Others relate how the "golden tree" shed spangles and nuggets of gold like leaves, and seeds, and how these particles of gold gathered in the soils and alluvium - an interesting origin indeed for eluvial and alluvial gold placers. Adams (1938) mentions a thesis in the University of Halle entitled De auro vegetabilipannoniae, written by a certain Huber in 1733, which presents a comprehensive study of the literature on the vegetable growth of gold. The translation of a part of this thesis as given by Adams (p. 295) is as follows:

And just as in these places there are growing plants, members of the Vegetable Kingdom, so not infrequently, by a natural spectacle which is altogether wonderful and delightful, it comes to pass that gold, as if joined with these vegetable growths by a bond of consanguinity, laying aside, as it were, its own metallic character, grows after the fashion of plants out of the same lap of Mother Earth. Between the gold and the vine, indeed, these observers relate that there exists so close an intercourse: that the gold not only embraces the vine externally under the form of threads after the fashion of a climbing plant: but that even the vine sometimes puts forth little shoots and tendrils of pure gold, sometimes little berries of the same metal between its leaves. Gold is found intimately associated not only with the vine but with other vegetable growths: occurring either twisted up in various manners with their roots, or else growing near them in the form of little strings or threads. And this species of gold springing after the manner of vegetable growths, or in the midst of them, we designate by the name of Vegetable Gold.

Huber apparently espoused the opinion then current that the gold grew like a plant, in some cases in dendritic or treelike forms, about the roots of vines. Gold associated with the roots of plants, especially those that are decaying, is not uncommon and is obviously the result of the reduction of auriferous soil solutions by decaying vegetation. In some places it is apparent that distorted nuggets of gold grew in this manner. Furthermore, it is interesting to note that the observation by the medievalists of enrichments of gold below trees has been amply confirmed by modern analysis of humus and mull developed in the A horizon of soils beneath heavy forest cover. A number of alchemists and early mineralogists believed that each metal began as a soft plastic material that they called gur or bur. This material oozed out of fissures and was probably ordinary limonite, fault gouge, and other unctuous substances like kaolinite and precipitated carbonates. There were still others who connected the veins and metals with the breathing of the earth, which was thought to function and exhale like a giant animal. This theory was current in the seventeenth century and was adopted by Kepler (1571-1630), the great German astronomer. The idea of the growth and transmutation of metals, however, held the general stage and greatly influenced the views of the old mining geologists. On finding bismuth, cobalt, and zinc in the veins instead of gold and silver, they said "We have come too soon," implying that the baser metals had not yet had sufficient time to be transmuted (ripened) into the noble metals. These and a host of other fantastic ideas were held from early medieval times until the birth of modern chemistry in the latter part of the seventeenth century. Even Robert Boyle, the "father of modern chemistry," in his Sceptical Chymist (published in 1661) could not quite bring himself to discard the views of the ancients about the magical growth and spontaneous generation of minerals in the earth. These Western ideas about the origin of mineral (gold) deposits had a parallel development in the Indian and Chinese civilizations that merits brief mention.

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Gold in: Gold 1 2 Primitive Classic Medieval Renaissance post-Renaissance period.
Gold: Deposits Transport

Rafal Swiecki, geological engineer email contact
February, 2006

This document is in the public domain.