Too perfect. Patterns look "snakeskin" or repetitive.
Tiny cracks on the surface. These can eventually break the stone. how to buy opals
Some opals absorb water and lose color temporarily. If you'd like to narrow this down, let me know: What is your budget range ? Do you have a favorite color (Fire red, ocean blue, etc.)? Too perfect
Look at the side. Straight, glued lines mean it's a composite. Pattern and Shape The way the color is arranged affects the price. Harlequin: Large, distinct squares of color. Rarest. Pinfire: Tiny dots of color. Common. Flash: Large blocks of color that blink on and off. These can eventually break the stone
Look for a high "cabochon" (dome). It shows off the color better. 🚩 Watch for Red Flags
Milky base. Softer, more feminine appearance.
Used to make cheap Ethiopian opals look like Black Opals.