Flame Opal

Flame Opal is a trade name for warm orange-to-red opal that glows like a flame, closely related to (and often overlapping with) Mexican fire opal. The vivid body color, caused by iron oxide, is the main appeal.

Most flame opal is transparent to translucent and can be faceted to bring out its rich color. Some stones display play-of-color flashing within the fiery body, which raises their value considerably, while others rely on body color alone.

Mexico is the classic source, with additional material from Ethiopia, Brazil, and elsewhere. Flame opal is a favorite for bold, warm-toned jewelry.

Flame opal forms when silica-rich water deposits hydrated silica in cavities of volcanic rock, particularly rhyolite. As the silica gel solidifies it traps trace iron, which gives the orange-to-red coloration.

In Mexico, the famous fire opal forms in gas pockets and fractures within rhyolitic lava flows, where hot, silica-bearing fluids precipitated the opal. The intensity of color depends on the amount and oxidation state of the iron present.

Because it crystallizes (technically, solidifies amorphously) at low temperatures near the surface, the opal can retain significant water, which influences its transparency and stability.

Identify flame opal by its bright, warm orange to red body color, vitreous luster, and transparent-to-translucent clarity. Any play-of-color appears as green or blue flashes against the fiery background.

Hardness is about 5.5-6.5, streak is white, and fracture is conchoidal with no cleavage. The stone may feel slightly warm and is lighter than many similarly colored gems.

Look-alikes include orange/cherry citrine, hessonite garnet, and carnelian, all of which are harder (citrine and carnelian ~7, garnet ~7-7.5). Glass imitations may contain bubbles. Mexican fire opal can sometimes craze, a clue not seen in the harder look-alikes.

Flame Opal is prized in jewelry, often faceted to showcase its glowing orange-red color, and used in rings, pendants, and earrings. Stones that combine body color with play-of-color are especially valuable.

Like all opal it requires gentle care: protect it from knocks, heat, ultrasonic cleaning, and drying, which can cause crazing or fracturing.

Metaphysically, flame and fire opal are linked to passion, energy, creativity, and the sacral chakra. These associations are spiritual traditions, not scientific properties.