Opal/ˈəʊpl/ Definition 1 of 2Pro Tip 1/3Jewelry Gemstone Opal is often used in jewelry like rings and pendants and is a symbol of beauty. He gave her a stunning opal ring. Pro Tip 2/3Play of Color The color play in opals can include a range of hues, likening to rainbows. The opal shimmered with a spectrum of colors. Pro Tip 3/3Varieties Abound Opals come in many types, such as 'fire opal', known for its warm colors. The fire opal necklace glowed with a fiery orange hue.