Why Choose Opal Rings? Discover Their Unique Beauty This makes opal rings a flexible and eye-catching option for people who are trying to leave an impression with their style & jewelry. When choosing an Opal Rings it is important to check & examine the opal. There are two main categories: the first one is precious opals and the other is common opals. Precious opals are further categorized into black opals, white opals, and crystal opals; each type has its own particular attributes and allure. Black opals are eminent for their black body tone, which gives striking scenery to lively play-of-color. White opals, then again, have a pale body tone that permits the play-of-variety to become the dominant focal point. Crystal opals are transparent to semi-transparent considering a more subtle display of color.