Silver, a lustrous precious metal, has captivated humanity for millennia with its unique properties. Renowned for its electrical and thermal conductivity and high reflectivity, these attributes have made silver indispensable across various applications, from historical coinage and jewelry to modern technology.
Estimating Earth’s Silver Reserves
Estimating the precise quantity of silver remaining unmined within the Earth’s crust involves complex geological and economic considerations. “Reserves” refer to known deposits that are economically and technologically feasible to extract at current market conditions. These figures are dynamic, fluctuating with new discoveries, advancements in mining technology, and changes in market prices, which can render previously uneconomical deposits viable. The U.S. Geological Survey (USGS) consistently tracks these estimates, providing the most current assessments of global silver reserves.
More recent USGS data from 2023 indicates total global silver reserves increased to 717,500 metric tons. Challenges in achieving precise figures arise because silver is often extracted as a byproduct of other metal mining, making it difficult to discern how much is intentionally versus incidentally extracted. Furthermore, unearthed silver is not uniformly distributed, with some deposits requiring advanced technologies to access.
Where Silver is Found
Silver deposits occur in diverse geological settings, often formed through hydrothermal, magmatic, and sedimentary processes. Hydrothermal processes, involving hot, mineral-rich fluids circulating through Earth’s crust, are a common mechanism for silver ore formation, frequently associated with volcanic activity. Magmatic processes can also create silver-rich ore bodies as molten rock cools and releases metal-rich fluids. Additionally, silver can precipitate from groundwater or accumulate in sedimentary rocks through sedimentary processes, though these deposits are less common.
The metal is primarily found in various types of ore deposits, including epithermal veins, polymetallic veins, and porphyry deposits. Globally, Peru holds the largest silver reserves, estimated at 140,000 metric tons. Other countries with significant reserves include Poland (170,000 metric tons), China (70,000 metric tons), Australia (92,000 metric tons), and Mexico (37,000 metric tons).
Silver in Circulation: Mined and Recycled
Beyond what remains in the ground, a substantial amount of silver has already been extracted and circulates within the global economy. Estimates suggest approximately 1.74 million metric tons of silver have been mined globally throughout history up to 2023, though precise figures vary. Annual global mine production was around 26,000 metric tons in 2022, decreasing slightly to approximately 25,830 metric tons in 2023. Mexico consistently leads in silver production, followed by China and Peru.
The “above-ground stock” refers to refined silver in use, encompassing items like jewelry, silverware, industrial components, and investment bullion. By late 2018, an estimated 1.6 million metric tons of physical silver were above ground, though much is not readily available for market supply as it’s held in fabricated products. Recycling plays an important role in the silver supply chain, contributing an estimated 25-30% of the global supply annually. In 2022, nearly 7,000 metric tons of silver were recovered through recycling, comprising about 28% of the overall supply that year.
The Future of Silver Availability
The long-term availability of silver is influenced by a complex interplay of increasing demand, potential for new discoveries, and advancements in extraction and recycling technologies. Industrial applications are driving a surge in silver consumption, particularly in green technologies like solar panels and electric vehicles. Each photovoltaic panel, for instance, requires approximately 20 grams of silver, and demand from the solar energy sector alone could rise by 170% by 2030. Silver’s electrical conductivity also makes it indispensable in electronics, including 5G infrastructure, AI hardware, and various connected devices, with demand in these sectors projected to triple by 2030.
While some discussions touch upon “peak silver,” suggesting a maximum rate of extraction followed by decline, this concept is often balanced by human ingenuity and technological progress. New technologies are emerging that can make previously uneconomical deposits viable, such as advanced bioleaching, AI-driven ore sorting, and robotic drilling. Furthermore, innovative recycling methods, like the Jet Electrochemical Silver Extraction (JESE) technology for recovering silver from solar panels, are becoming important for supplementing primary supply and addressing potential deficits. These advancements, alongside the reprocessing of mining waste, contribute to a more sustainable long-term outlook for silver availability.