Have you ever thought about the wonderfully shiny sterling silver piece that adorns your neck, ears, or wrists? What it is, where it’s from, and how it got here? Silver is ubiquitous in the jewelry industry, and widely used in many others, but there is a certain disconnection between the mines where metallic ore containing silver is excavated, and the world of high fashion where silver has reigned for millennia. If you love metal accessories as much as we do, you might enjoy a brief walk through all the hard work that goes into turning raw silver into a beautiful chain, and an understanding of why silver and gold chains are as expensive as they are. You just might come out of it with an even greater love and respect for your favourite silver jewelry!
Before anything, a site is chosen that has indicated high levels of natural metal deposits in the Earth. Once a candidate has been decided upon, the site is scrutinized by environmental specialists and mining engineers in a series of studies, tests, and calculations. Since there are rigorous government controls on mining, the very confirmation of a piece of land as the future site of a mine can be a 2-5 year process. The mining company is also obligated to ensure, before any construction begins, that after the site has been depleted of valuable minerals there will be an environmental rehabilitation process to restore the land. Huge amounts of expertise and critical thinking go into making mining projects safe, environmentally sound, and effective- before they’ve even started construction! There are generally two types of mines: surface level mines, which surround their site like an enormous football stadium, and underground mines, which can be located deeper than a mile underground, where they carve out a virtual subterranean society. Either way, the scale is huge and the technical coordination is astounding.
Silver, like all metals, is found as a mineral encrusted below the earth’s surface. What many may not realize is that silver, copper, lead, and gold are most frequently mined in the same place and found in the same ores, and separated afterward. Only about a quarter of all silver produced is mined from ores that are specifically harvested for silver. Even from those rare ores predominantly made of crude silver, trace amounts of copper, lead, and gold will be recovered and saved, just as trace amounts of silver are recovered from lead, zinc, and copper ores.
Once the ores are recovered from the earth through painstaking physical labour and specialized mechanical machinery, they are shipped from the mine to a reduction plant to be milled. Reduction plants (also called ‘mills’) are usually located adjacent to or nearby the mine itself, established alongside the realization that the site will be profitable for years to come.
At the mill, the ores are ground into powder into giant drums to increase surface area, quickening the effect of metallurgical chemicals. Various metallurgical extraction processes are employed to isolate the desirable elements, ridding the original ore of unwanted impurities like antimony, arsenic, and tin, and separating usable metals like copper, lead, zinc. After all chemical treatments, intense heating, and physical separation, silver can emerge as pure as 95%.
At that point, it is shipped to a precious metals refinery. There the silver is soaked in nitric acid, dissolving into the mixture. Silver precipitant crystals are added to the solution, and the acid is drained and neutralized. The result is pure silver in the 99th percentile!
Alloys and Wire
Pure silver that will be used in the jewelry industry then typically gets shipped to a wire factory. There it can be alloyed with other metal to produce sterling silver, also known as standard silver, which is 92.5% silver (the remainder typically composed of copper). Sometimes sterling silver is also referred to as 0.925 silver. The alloy is heated yet again to become soft, and drawn through specially cut dies to be formed into wire. Depending on the width of the die, different gauges of wire are created.