Types of Opal: A Complete List of Opal Varieties
A complete, plain-English list of the types of opal, grouped by body tone, host rock and origin, with a word on doublets and which to choose.
Richard Lewis
How Are Opals Made? Opal Formation and Mining
How opals form over millions of years from silica and water, where they are found, and how they are mined at Coober Pedy and Lightning Ridge.
What Is Opal? A Jeweler’s Plain Guide
What is opal, in plain terms: what it is made of, why it is not a crystal, the difference between precious and common opal, and where it comes from.
White and Crystal Opal: A Jeweler’s Guide to the Lighter Opals
White and crystal opal explained: how the transparent crystal and milky white opals differ, where they come from, what they are worth, and who each suits.
Australian Opal: The Benchmark of the Opal World
Australian opal, the benchmark of the opal world: the great fields (Lightning Ridge, Coober Pedy, Queensland), why it is so prized, and how it compares to Ethiopian.
Boulder Opal: A Jeweler’s Guide to Opal in Ironstone
Boulder opal explained by a jeweler of 50 years: opal in ironstone, why the rock backing makes it tough and vivid, where it comes from, and why it is not a doublet.
Fire Opal: A Jeweler’s Guide to the Glowing Opal
Fire opal explained by a jeweler of 50 years: what makes it glow, why it is named for body color not play-of-color, where it comes from, and how to wear it.
What Is Play-of-Color? How Opal Makes Its Rainbow
What is play-of-color in opal? A jeweler explains the silica-sphere physics behind opal’s rainbow, which colors are rarest, and how pattern affects value.
Opal Meaning and Symbolism: Folklore, Birthstone and What Opal Represents
Opal meaning and symbolism: the folklore, the bad-luck myth debunked, opal as the October birthstone and 14th anniversary gift, and what opal represents.
Black Opal: Why Lightning Ridge’s Finest Is the Most Prized
Why black opal is the most prized opal: what ‘black’ really means, where it comes from, and how to judge body tone, brightness, pattern and color.