The main examples of precious metals are gold, silver and platinum.
goldis a valuable yellow metal. Gold is generally found in metamorphic rocks. It is found in underground rock veins, where the interior of the Earth heats the water that flows through the rock.
Worldwide, we have an estimated 69,000 metric tons of platinum reserves, and 95 percent of them are found deep in the Earth's crust in South Africa. Minuscule quantities are found in Russia and North America, where nickel and palladium are extracted as a by-product, respectively. Digging up all this material has a high cost to the environment. Extractive industries are responsible for about 40% of the world's carbon emissions and about 10% of biodiversity loss, according to the UN Global Resources Outlook report.
In the last 50 years, material extraction has tripled. Many resources are now increasingly difficult to find, more expensive, and the environmental costs of extraction are increasing. Despite the fact that South America was Europe's treasure trove of gold and silver from the 1530s to the late 1700s, at the beginning of the 21st century, the region only contributed a small percentage to the world's production of these precious metals. Brazil is the main gold producer in South America, with deposits in the Amazon basin accounting for much of the production.
Traditional mining centers in Minas Gerais, Goiás and Mato Grosso have declined in importance. Placer deposits in the Atrato River basin in Colombia are important sources of gold, and the metal is still produced also in Venezuela and in classical gold mining centers in the central Andes of Peru, in the Andes of Chile and in the Carajás area of Brazil. Peru has historically been one of the world's leading silver exporters, mainly from mines that stretch from Cerro de Pasco to Huancayo in the Andes, but production has declined since the early 1970s. Ecuadorian silver is mainly found in the Andes, while Colombia, Argentina and Bolivia also exploit this metal in their mountainous areas.
Platinum is found in Colombia's Western Cordillera, as well as in smaller quantities, in association with copper mining activities in central Peru. Its free cash flow and a prospect of lower volatility for base metals, combined with a possible advance in the trade war, could push stocks higher in the second half of this year. Ultra-high-precision analyses of some of Earth's oldest rock samples by researchers at the University of Bristol provide clear evidence that the planet's accessible reserves of precious metals are the result of a meteorite bombardment more than 200 million years after the formation of the Earth. In the short term, demand for metals used in catalytic converters is expected to remain stable, driven by increased car sales in Asia.
Iridium is one of the rarest metals in the Earth's crust, with an annual production of only three tons. Palladium is the most expensive of the four main precious metals: gold, silver and platinum are the others. That has led to a large gap between sister metal prices, with excess platinum struggling, but it is now about to gain lost ground. Gold and silver, and sometimes other precious metals, are often seen as a hedge against inflation and economic recession.
However, precious metals are tens or thousands of times more abundant in Earth's silicate mantle than expected. A metal that is currently in high demand is cobalt, a crucial component of lithium-ion batteries for smartphones and electric cars. This month alone, rhodium prices have risen by more than 30 percent, and one of its main drivers is its enforcement in emissions standards, which is now stricter and is driving much greater demand for this precious rare earth element. Research examining discarded televisions in China also showed that large quantities of gold and copper could be obtained at a lower cost than removing metal from the ground.
Other precious or semi-precious stones abound in the same region, in particular topazes, tourmalines, beryls, aquamarines, chrysoberyls, garnets, opals and sapphires, as well as quartz of a sufficiently high grade for use in the electronics industry. Bronze, iron and brass were, then, the metallic materials on which successive peoples built their civilizations and with which they manufactured their instruments for both war and peace. . .