One widely accepted hypothesis proposes that many gold deposits, especially those found in volcanic and sedimentary rocks, formed from circulating ground waters driven by heat from bodies of magma (molten rock) intruded into the Earth’s crust within about 2 to 5 miles of the surface.

What is the origin of ore?

Ore is extracted from the earth through mining and treated or refined, often via smelting, to extract the valuable metals or minerals. Ores must be processed to extract the elements of interest from the waste rock. Ore bodies are formed by a variety of geological processes generally referred to as ore genesis.

When was gold ore first discovered?

January 24, 1848
Gold Discovered in California. Many people in California figured gold was there, but it was James W. Marshall on January 24, 1848, who saw something shiny in Sutter Creek near Coloma, California.

Is Diamond an ore?

There is no mineral ore of diamond. An ore is a rock which is crushed, refined, treated & something is retrieved from it by physical or chemical processes. Diamonds are found within kimberlite, & in Australia in lamproite, but diamond is a crystal of carbon & is not part of the rock, so the rock is not an ore.

Where is gold ore found in the world?

Most of that gold has come from just three countries: China, Australia, and South Africa. The United States ranked fourth in gold production in 2016.

What kind of origin does an ore deposit have?

An ore deposit may be either of igneous or of sedimentary origin. Some deposits are related to metamorphic processes and are as such classified as deposits of metamorphic origin. Within these three broad modes of origin, a mineral deposit of economic value might have originated due to set of simple or complex processes.

What kind of gold is there in the world?

Massive, base metal arsenical gold ores are rare, and there are only a few deposits in the world. A typical arsenical gold ore contains arsenopyrite as the major arsenic mineral. However, some arsenical gold ores, such as those from Nevada in the USA (Getchel deposit), contain realgar and orpiment as the major arsenic-bearing minerals.

How to determine the nature of gold ore?

Determination of preg-robbing and refractoriness of the ore/concentrate. Sequential diagnostic tests to determine nature and extent of gold tied-up with different sulfide and non-sulfide mineral constituents. Detailed mineralogical characterization (petrography, X-ray diffraction, and fluorescence, electron microprobe).

How did gold come to be on Earth?

Present theory is that gold and other heavy elements would have been evenly spread in the forming Earth. However, the percent of gold present in interstellar matter is extremely minute. As the core melted, gold would amalgamate along with iron and nickel.