The most popular option for silver jewelry, sterling is 92.5 percent pure silver alloyed with other metals, usually copper. Sterling silver has some advantages over fine silver: It's workable and brilliant, and sterling is more durable than pure silver. The copper and other metals in the alloy reduce its tendency to tarnish. Sterling usually bears a stamp of purity featuring the number of its parts per thousand of pure silver, 925.
Most of my earring designs contain sterling silver components because sterling silver is friendlier to sensitive earlobes than other silver toned metals. Although wearing sterling jewelry shouldn't cause it to tarnish, prolonged exposure to oxygen will. If you want your sterling to stay shiny, store it in a relatively airtight container. I keep some of silver jewelry in plastic zip-top bags, inside a jewelry box. The pieces I wear often are loose in a jewelry box, and are tarnish-free.
Fine (or Pure) Silver:
Jewelers refer to pure or nearly pure silver as fine silver, which is 99.9 percent silver, often expressed as 999 parts out of 1,000. When buying fine silver jewelry, look for simple shapes that will not lose their detail if the jewelry becomes dented or bent. Items with a hammered finish are a good choice because they will not show wear as a brushed or polished finish might. Silver products from the Karen Hill Tribe in Thailand are very popular for jewelry making.
Silver Plated Jewelry:
One solution to the rising cost of silver is to use silver plated materials. The two most common methods of plating a base metal with precious silver are electroplating and filling. During electroplating, silver atoms in a solution are permanently bonded to a piece of jewelry made from base metal using electricity. As the current passes through it, the silver is attracted to it and forms a sheath of precious metal over the object. This coating is durable but thin; over time, it can wear away to reveal the common metal beneath it. However, this wear can take years with careful maintenance. When you see jewelry marked as "silver plated," it's usually electroplated.
There's a wide range of quality in silver-plated jewelry components, so my preference is silver-plated pewter products, especially those made by Tierra Cast. Their designs are excellent, I can trust their quality, and the components don't tarnish or peel.
Silver-filled jewelry also involves a thin outer layer of fine or sterling silver over a less expensive metal, but this outer layer is thicker than the outer layer in silver plated materials. Silver-filled components are made by pressing and heating the silver to bond it to the base metal. I buy silver-filled components marked 925/10, which means the silver layer is 10% of the metal. I use silver-filled items such as crimp covers, headpins, beads, and clasps.
Pure Silver over Copper:
These components are electroformed with an extra thick coat of pure silver (99.9%) over a copper core. They tarnish less easily than traditional sterling and will polish to look brand new. They're also hypo-allergenic and serve as a great cost-effective alternative for people with sensitive skin. I often use this type of silver beads in my jewelry because their quality is high, they have wonderful designs, they're durable, and they look great combined with other types of beads.
Caring for Silver Jewelry:
Body oils, chemicals, and exposure to air can cause silver to darken. This darkening is known as patina, tarnish, or oxidation, and it I've heard that it happens more often with sterling silver (which contains copper) than with pure silver. Although many people love wearing silver jewelry with an antique-looking patina, others prefer shinier silver.
There are steps you can take to keep your silver shiny. First, wipe off fingerprints, perfumes, and tarnish with a lint-free polishing cloth. Second, store your silver jewelry in an air-tight container.
I've seen several pins and posts advocating various ways of preventing tarnish or treating it, but have't tested them. I simply keep my own silver in a somewhat airtight, felt-lined jewelry box, and wipe it with a polishing cloth as needed. For long-term storage, I keep silver components and jewelry in sealed plastic bags with anti-tarnish strips.