Material: Gold Filled Silver 925K (20% Gold out of the weight) Each piece of our jewelry is hallmarked GF 18K Gold-filled jewelry is a layer of gold bonded to the surface of silver using heat and pressure, great economical alternative to solid gold. it can last as long as solid gold and won't tarnish or rub off. it should last somewhere between 10 to 30 years. What’s more, it costs a fraction of the price of high carat gold pieces. It’s a win-win! We included opal inlay in many of our Historical Designs inspired jewelry collection. The color of the opal jewelry changes depending on the angle of its light reflection. History the ankh is an ancient Egyptian hieroglyphic symbol that was most commonly used in writing and in Egyptian art to represent the word for “life” and, by extension, as a symbol of life itself. The ankh has a cross shape but with an oval loop in place of an upper bar.