About OpalsA gift idea that’s 6,000 years oldThat’s the age of opal artifacts found in Kenya. Opals have long been considered magic; maybe it’s those mysterious colors that shift and change across their surface. Opal is the birthstone for October. Color and pedigreeOpals flash a rainbow of iridescent colors, an effect that’s called play-of-color. White and black are most common, but you’ll also find gray, red, orange, yellow and brown. Most opals come from Australia. Taking it homeOpals rate 5 1/2 to 6 on the Mohs Hardness Scale. Opals need more tender care than many stones, since they’re only a bit harder than glass. Mild soapy detergent and water is the best way to clean opal jewelry. Never use ultrasonic cleaners. Visit the Learning Guide for more information on opals. About GoldGold is more than just a pretty facePeople don’t just love gold because it sparkles; for centuries, it’s been cherished for being strong. Gold is also malleable enough to suit endless designs, so it’s an excellent foundation for all types of jewelry. And because it’s resistant to corrosion, tarnish and rust, your gold jewelry will look new for a long time. Gold is very malleable making it ideal for jewelry designs, but to give it the strength needed for it to withstand wear it must be alloyed with other metals such as copper, silver, zinc or nickel. The percentage of pure gold to alloys is expressed in karatage. 24k would represent pure gold. 14k represents 14 parts gold and 10 parts alloy. In the United States fine jewelry is generally created using 18k, 14k or 10k gold. Yellow GoldThe shade of yellow gold can vary based on the alloy. As the amount of gold increases, so does the brightness of the yellow color. Visit the Learning Guide for more information on yellow gold. White GoldWhen yellow gold is mixed with nickel and zinc, it becomes white gold, which looks similar to platinum. White gold is often finished by plating it with rhodium, which will give it an even whiter, more brilliant appearance. Visit the Learning Guide for more information on white gold. | 
