Gold is one of the world's most abundant precious metals and is the oldest known to humankind. Due to gold's magnificent properties and wonderful luster, it is considered to be the most important metal in jewelry making. When purchasing a piece of gold jewelry consider the karat of the gold. The higher the karat, the more durable the item will be and closer you are getting to pure gold(24k), therefore the higher the price will be. Karats also factor into the color of the gold. For example, 18k is going to be a brighter golden yellow than 10k. Gold alloys, aside from strengthening gold for jewelry, can also affect its color.
Platinum is pure, rare, eternal. It never fades or tarnishes and is so pure, that it is naturally hypoallergenic and ideal for those with sensitive skin.
Platinum's unequaled durability and resistance to wear makes it the most secure and protective metal, which means your jewelry will be protected for a lifetime of wear. The density of platinum makes it more durable than other jewelry metals and rarely loses shape since it's a much harder metal. As it's denser than gold, a platinum ring will be around 60% heavier than a similar one in 14k, or 40% heavier than one in 18k.
Palladium is the newest trend in jewelry. Alone or alloyed with silver or gold, palladium offers many of the same metalworking properties as Platinum, and remains tarnish free. It is more precious than silver and whiter than platinum. Because it is also lighter than platinum, nearly half the weight, more intricate necklaces, and bracelets can be made capable of bearing larger gemstones with no gain in overall weight.
Sterling silver is the most lustrous, most plentiful and least expensive precious metal. However, silver tends to tarnish, making it less popular in some forms of jewelry. Like gold, silver is too soft for use in its pure state and must be combined with other metals for durability. When silver oxidizes/tarnishes it first turns a yellow color and darkens with time to be dark graphite grey or nearly black. Since silver will discolor or tarnish over time from being exposed to air, a protective coating of rhodium will be plated over the silver on some jewelry. Over time these finishes will wear off, but they do provide an extended time before oxidation occurs.
Ceramic jewelry is not made like glazed pottery or glass. It’s manufactured using inorganic, engineered, and non-metallic materials. It’s not technically a metal but is often displayed with contemporary metals. Since ceramic is one-third the weight of gold, jewelers can design bold, lightweight, and comfortable pieces. Although it’s tough and scratch-resistant, it can chip and break. Ceramic cannot be resized or repaired.
When cobalt is alloyed with other metals for use in jewelry, it produces a very white, very hard, and scratch-resistant metal. It’s so hard, in fact, that jewelry designers have to use diamond-tipped tools to cut it. Cobalt is hypoallergenic but cannot be resized or repaired.
Stainless steel, a very common material that you'll see just about anywhere you look: in cutlery, cooking utensils, countertops, sinks, plumbing hardware, and car parts. Is a relatively hard and durable metal. Steel is the most inexpensive of alternative metals for wedding bands. However, it cannot be resized but can be cut-off in the event of an emergency, though they are difficult.
Titanium is a natural element which has a greyish-silver color. Titanium is the hardest natural metal in the world. It is very strong, more dent, bend, and scratch resistant than gold, silver, and platinum, is lightweight, hypoallergenic, and offers an exotic array of colors which other metals simply do not. Titanium cannot be resized, but can normally be cut-off the finger in the event of an emergency, though they are more difficult to cut-off than any precious metal.
Tungsten Carbide, also referred to simply as Tungsten, is a very hard, strong and durable metal. It's also quite heavy.
Tungsten has a characteristic unique to this special metal - tungsten is highly scratch resistant. Unlike other metals, tungsten rings do not scratch with everyday wear. It is technically possible to scratch tungsten, though only with objects that are harder than it, which is very few. Tungsten stands up to the wear that even the roughest husbands can dish-out, making it a popular choice for men's wedding rings. The tungsten color is a grey-white color, similar to that of white gold or titanium but darker. Tungsten rings cannot be resized or repaired. In case of an emergency, Tungsten rings can be 'crushed' off.