Tungsten Ring With Australian Opal Inlay, 4mm Comfort Fit Wedding Band Tungsten carbide Genuine Australian Opal Chip Inlay Waterproof Epoxy Coating Protects inlay 4mm Wide Comfort fit design Matching 6mm band available Includes free ring box Tungsten, also known as wolfram, is a chemical element found on the periodic table. It gets its name from a Swedish phrase meaning ?heavy stone?, indicative of the metal?s weight and strength. Tungsten is often described using superlatives. Here are some: * Tungsten has the highest melting point of all metals * It is the heaviest metal used in jewelry * It is the hardest and most scratch resistant metal * It is the most popular metal for men?s wedding rings in America Tungsten vs. Tungsten Carbide: Although often used interchangeably, there are differences between these two terms. Tungsten in its pure form cannot be used in jewelry. Instead, it is formed into a metal, consisting of approximately 85% tungsten and 15% carbon, nickel or cobalt which is known as tungsten carbide. Because tungsten is very brittle, mixing it with carbon reduces this characteristic, making the metal more durable and easier to work with. The nickel or cobalt acts as a binder, holding the metal together and making it possible to shape it. Tungsten carbide with a nickel binder is considered top quality and ideal for wedding bands. However, tungsten carbide with cobalt as a binder is not recommended for jewelry as the cobalt, which tends to react with body oils, can cause skin irritations and staining. As we?ve just mentioned, tungsten carbide contains carbon. Tungsten without carbon is just a steel ring, with a Mohs of 7.5. It can still get scratched and damaged. However, when carbon is added into the mix to create carbide, the resulting metal becomes extremely tough and durable. Some vendors sell tungsten rings but call them tungsten carbide. So take care as not every tungsten carbide ring on the market is actually carbide.