The early alchemists had recipes listing ingredients or techniques by which they made metals. The basis for many of these recipes was to introduce to base metals properties which the metals lacked. Today this is unreasonable, genuine gold no matter the length that it is heated never changes color.
However, it must be said, that modern jeweler’s gold would not pass this test because it usually contains certain amounts of copper, and therefore will change color. But the early alchemists, it must be remembered were not knowledgeable of this fact concerning true gold.
Also, these alchemists were not aware that each metal has a specific gravity or weight. No other metal can match it. Therefore, these alchemists figured if through a process they got a metal appearing like gold or silver, they had produced the metal.
The processes usually involved one of two techniques: either preparing white or yellow alloys by fusion or coloring the metal’s surface.
Their reasoning for doing this was that if another metal had the property of whiteness or yellowness, that property could be removed from that metal and inserted into the metal which lacked the property. Color was considered an “activity” of the metal, its pneuma or spirit.
By adding a color which the metal lacked, the alchemists considered that they were giving it spirit, enriching it. Needless to say, white metals were easier to come by because there are many more white alloys with similar densities as silver but fewer yellow ones, all of which are less dense than gold.
Most attempts at this were unsuccessful, but there were exceptions were the coincidences of color between the reagent and the product that seemed to support the rule.
In the case of producing silver white alloys of various metals were generally used. These were usually alloys containing copper, silver, and arsenic. In this particular recipe it was indicated that if copper was “whitened,” its alloy with silver would not have a dark color.
In another recipe named “Making of Silver with Tutia” the alloy preparation contained silver, lead, zinc, and copper. All alchemists of the age did not regard the whitening of copper the making of genuine silver, but it is a prime example of altering the color of a metal.
Again one must be reminded most true alchemists took their art seriously and were honest, but their primitive methods left much room for charlatans.
The apparent successes in making gold were much easier to come by. The early recipes of the alchemist generally included these four methods:
The making of yellow alloys of base metals, much like brass.
The preparation of debased gold.
The superficial coloring of metals or alloys.
A series of very complex processes in which distilled liquids were employed or in which metals were subjected to the actions of vapors.
Most of these methods were employed in the production of brassy alloys of copper, tin, and zinc, which in modern times are called ormula, oroide, Mannbein gold, and so on, and were certainly known to Greek alchemists.
Although zinc in metallic form was not known then, these alloys were prepared from smelting mixtures of other metals or their ores with cadinia, a mixture of metallic oxides containing various proportions of zinc found as deposits in flues of smelting furnaces. It is highly unlikely any of these methods produced a single ounce of gold that a goldsmith would accept, but the yellow appearance gave hope for success.
The most successful attempt at making gold was called “doubling” gold, which doubled the weight of gold. (See Doubling According to Moses) Greek alchemists knew it as diplosis.
It basically was supported by the fact that while silver lends a greenish tent to gold, and copper a reddish tent, the admixture of both silver and copper hardly changes its tent at all.
Most likely the alchemist did not think that he was falsifying gold, rather he saw the gold as acting as a seed which, nourished by the copper and silver, grew at their expense until the entire mass was gold.
Some preparations of alloys in this manner today are legal on the European Continent; just as are 18-carat and other gold-copper alloys are in Great Britain. A.G.H.
Taylor, F. Sherwood. Alchemists, Founders of Modern Chemistry. Kessinger Publishing. pp. 30-35