G & S HUB

The metal

What silver is

Silver is the element Ag, atomic number 47, named from the Latin argentum. In Tamil it is called velli. It is a soft, white precious metal, and among metals it conducts heat and electricity best. A polished face throws light back almost like a mirror.

In the ground it is sometimes native silver, metal already free. Far more often it is held in minerals. Acanthite, a silver sulfide (the form once called argentite), is one of them. More of the world’s silver rides inside other ores: galena, the lead sulfide, and the zinc and copper ores mined beside it.

The mine

How it is mined

Two kinds of mine open the rock. When the ore lies near the surface, the working is an open pit, cut in steps called benches. The rock on those benches is broken and hauled out by truck.

When the ore runs deep, the mine goes underground. A vertical shaft or a sloping decline reaches the vein. Horizontal tunnels, called drifts, follow it. The ore is taken from openings called stopes, then lifted or trucked to daylight.

Most newly mined silver is not the only metal the mine was built for. It comes out while lead, zinc, copper, or gold ore is processed. Some mines are primary silver mines, worked for silver itself.

From ore to metal

Ore, concentrate, metal

The rock is crushed and then ground fine. For the usual sulfide ore, froth flotation lifts a silver-bearing concentrate and leaves the waste behind. Some ores are leached instead of floated. Either way the aim is the same: a small weight of rich material, not a mountain of rock.

The concentrate is smelted. Silver that travelled with lead is parted from the lead bullion. Silver that travelled with copper is recovered from the residue of electrolytic copper refining. A last refining step, commonly electrolysis, brings the metal up to fine silver.

Purity

.999 and sterling

Fine silver stamped .999 is 999 parts silver in 1,000, which is 99.9 percent. Coins and bars are sold at this purity. The metal is soft, so a coin will mark and a thin sheet will bend. Where the air carries sulfur, the surface tarnishes to a dark sulfide film. The film is only on the surface.

Sterling is 925: 92.5 percent silver, the rest usually copper. The copper makes it harder, which is why a bangle, an anklet, or a chain that must hold its shape is often sterling rather than fine. Coins on this board are priced as fine silver, by the gram.

Coin and ornament

Why coins and ornaments

Silver became a coin metal because it is scarce enough to be worth keeping, bright enough to recognise, and simple to divide by weight. A fine silver coin is still sold that way: so many grams, at the day’s rate.

As an ornament it takes a stamp, a chase, and a small bell. It is heavy enough for an anklet to be heard when someone walks, and white enough to sit beside a bridal silk. That is why the same metal is both a coin in the palm and an anklet on the ankle.

Tamil Nadu

The Tamil pieces

The anklet often has a row of small bells. The sound belongs to the jewel. The bell-shaped earring is made in this house in silver. Silver bangles are worn singly or in a stack.

The silver coin is given at a wedding, kept by the household lamp, and offered at a temple. The waist belt is made in this house in silver.

This house is in Salem, Tamil Nadu. The metal is mined and refined elsewhere, then worked and sold here as ornaments and coins.