GOLD AND SILVER

                                                                GOLD 

Who hasn’t heard about gold? From childhood and beyond, the word “gold” means wealth and power to most people. So practically everyone gets interested whenever the word “gold” is mentioned. 

Gold is a “noble metal,” meaning it does not rust nor lose its shine. 

Gold occurs naturally in the Earth’s crust and can be concentrated via three main processes; namely, 1) magmatic activity (= molten rock), 2) hydrothermal activity (= driven by heated underground magmatic fluids, e.g. hydrothermal veins), and 3) metamorphic activity (heat and pressure). 

There is also a fourth process: placer deposits, on the Earth’s surface, and involves  weathering/transport plus reworking via running water. 

 

Note: “Porphyry” gold deposits are associated with low-grade igneous intrusions in the 

Earth’s crust.

Primary gold is referred to as lode, whereas reworked gold (i.e., occurs in stream and river beds) is referred to as placer deposits. 

“Porphyry gold deposits” are associated with low-grade igneous intrusions. 

Gold can also occur in “greenstone belts,” which are metamorphosed volcanic and sedimentary rocks, like the “Banded Iron Formations (BIFs).”

In sum, there is a considerable amount of terminology associated with “gold deposits.” 

The value of gold varies daily these days. As of March 21, 2026, the price of gold was approximately $4,504 dollars per ounce! Next week, no doubt, it will have a different value! 

          Figure 1. A hand-specimen of gold (2.5 inches wide). Image via the Smithsonian Institution.

                                                                   Silver

                                                                          

         Figure 2. A hand-specimen of gold (dimensions unknown). Image via the Smithsonian Institution.                       

                                                                  

Silver, whose chemical designation is “Ag,” occurs mainly with hydothermal-veiw deposits, which are commonly associated with igneous intrusions and volcanic activity. Silver is rarely found as a pure, native metal. Rather, it is usually combined with sulfur, arsenic, and antimony, and especially in association with lead-zinc and copper nickel ores. Furthermore, most silver is produced as a by-product of copper, lead, and zinc refining.

REFERENCE 

WIKIPEDIA, 2026