What Does Opal Look Like? A Visual Guide to Opal Patterns
A visual guide to what opal looks like: body tone, the main play-of-color patterns, which colors are rare, and how the main types appear.
Opals
Rare Opal Varieties: Harlequin, Contra Luz and Other Prizes
The rare opals collectors chase: harlequin, contra luz, red-on-black, Yowah nuts and Virgin Valley, and what makes each so sought after.
Opalized Fossils: When Ancient Life Turns to Opal
Opalized fossils are shells and bones that slowly turned to opal. What they are, how they form, where they are found, and whether you can wear one.
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.
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.