The origin of gold

These two types of mineralizing agents do not exist for gold nor for metals like him. There is no sense in geochemistry, gold deposit. Worse, he largely disappeared !

The reason is simple, gold is a sidérophile element. It is this strange property that caused his disappearance. Sidérophile means loving iron (σιδεροs the Greek Sideros, iron). Yes, it is iron the mineralizing agent. During the differentiation of the planet, the molten iron has percolated through the mantle silicates to form the inner core of the Earth, taking with him all siderophilic elements, including unfortunately the gold.

The siderophilic chemical elements have virtually no affinity for oxygen, so just the opposite lithophilic elements. Accordingly gold oxide is an unstable compound a thermodynamic point of view. The siderophilic elements form stronger bonds with the carbon or sulfur, but this affinity for sulfur is insufficient to separate when there is competition with chalcophile elements. They have a very strong chemical attraction to sulfur.

The siderophilic elements are high-density transition metals. The transition metals are elements in which the sub-layer is incomplete or the cations of which have that criterion.

The sidérophile interaction is based on a completely different type of chemical bonding that ionic or covalent bonds. This is the metal bonding * which occurs between the gold and the iron in the solid iron-nickel seed.

* Metal binding: electromagnetic interaction between the valence electrons delocalized, embedded in a « sea of ​​electrons », and the cores of the metal in a crystal lattice.

GOLD AND LITHOSPHERE

The lithosphere, consisting essentially of silicates, is not fertile ground for hosting and especially to concentrate the gold. As we have seen, the refuge of the primordial or sits in the heart of our planet. Indeed, what she inherited during planet formation is almost completely disappeared mantle because of the affinity of gold for iron. When iron retired at the center of the Earth, gold was also won, with much of the other siderophilic elements, and also with sulfur, selenium, tellurium (although for the latter elements another leak occurred since their hydrides are volatile).

In fact, it is likely that gold gleaned by the Celts in the Ardennes therefore follows that the crumbs that have escaped the large laundry with iron. Of course there are still and placer gold mines, we’ll talk. Obviously there are good reasons to think so, and taking into account the amounts included in the iron core, there is the solar abundance of this element, gold. But this does not console Bruno … This will require some new processes intervene to still concentrate the gold particles and make large nuggets.

Because everyone knows that there are gold mines in South Africa, Congo, Australia, Russia … These mines are active and the annual harvest is estimated at 2,500 tonnes in 50 years. These mines are even listed, it is to say *. The amount of gold extracted may seem important because we are conditioned by its rarity. But if gold had not had this sidérophile character (but that would not have been either gold), there would be similar amounts to those of lead or uranium. We will try to explain the origin of these mines which at first sight are in contraction with our words.

Despite its vast spread in the coat, lifts vein followed very subtle process of enrichment, which the bacteria can also be involved, explain (that is our hope) the origin of the gold.

* If there is an investor reader, here is an opinion:

the paper gold (ETFs) are bought and sold like physical gold, while only one-hundredth of ringing reserves and cents. If those who hold gold paper decided all together at the same time, to claim their physical delivery, only 1 out of 100 customers would be delivered (CN) They also receive as currency.