No — this superstition originated from a 19th-century novel and has no basis in reality. Opals have been considered lucky in most cultures throughout history.

Can opals crack or dry out?

Solid Australian opals are very stable. Ethiopian opals (hydrophane) can absorb water and may crack if they dry out too rapidly. All opals should be kept away from extreme heat and stored with some moisture in very dry climates.

Opal Buying Guide – How to Buy an Opal

Opals are unlike any other gemstone — their value comes from play-of-color, an optical phenomenon that creates shifting spectral colors across the stone's surface. Evaluating opals requires a completely different eye than grading diamonds or sapphires. This guide teaches you what to look for, what to avoid, and how to find the best opal for your budget.

Understanding Play-of-Color

When evaluating an opal, hold it under a single point light source (like a desk lamp or penlight) and rock it gently. Observe: How many colors do you see? (Red is rarest and most valued, followed by orange, then green and blue.) How bright are the colors? (Bright, vivid play commands premiums over dull, muted play.) What pattern do the colors form? (Large patches and harlequin patterns are most valued.) How much of the stone shows play? (Face-up coverage matters.) Move the stone through different angles to see the full range of play. GemstoneAI can help you capture and assess play-of-color quality from video.

Australian black opal showing bright play-of-color with multiple colors visible

Black vs Light vs Boulder: Choosing Your Type

Your opal type choice depends on budget and aesthetic preference. Black opals (Lightning Ridge) offer the most dramatic play-of-color against a dark background — they're the most valuable but start around $500/ct for good quality. Boulder opals (Queensland) provide natural dark backgrounds at more accessible prices — $100-$1,000/ct for fine stones. White/light opals (Coober Pedy, Ethiopia) are the most affordable — $20-$200/ct for good play. Crystal opals (transparent) can be stunning and range widely in price. For first-time buyers, boulder opals offer the best balance of drama and value.

Black opal: Most prestigious, vivid play on dark body — $500-$10,000+/ct
Boulder opal: Natural dark ironstone backing — $100-$1,000/ct — great value
White/light opal: Most affordable — $20-$200/ct — good for pendants
Crystal opal: Transparent body, bright play — $100-$2,000/ct
Ethiopian opal: Beautiful but hydrophane — $20-$300/ct — buyer beware

Doublets, Triplets, and Synthetics

The opal market includes assembled stones (doublets and triplets) and synthetics that can confuse buyers. A doublet is a thin slice of natural opal glued to a dark backing — it shows genuine play-of-color but at a fraction of solid opal prices. A triplet adds a clear cap on top, further reducing cost but also beauty. Synthetic opals (Gilson, Kyocera) show a characteristic 'lizard skin' or 'snakeskin' pattern under magnification. Always ask whether an opal is solid, doublet, triplet, or synthetic. Doublets and triplets should not be immersed in water as the glue can deteriorate.