Pineapple Opal

Pineapple opal—also known as ananas opal—is an exceptionally rare variety of precious opal found exclusively in the White Cliffs region of New South Wales, Australia. These specimens are named for their distinctive pineapple-like shape, formed by the replacement of a spiky, radiating mineral structure.

Fewer than a few hundred authentic pineapple opals have ever been documented, making them one of the rarest opal types on Earth. Their scarcity, combined with their bizarre and beautiful form, makes them highly coveted by mineral collectors and museums. Top specimens can command very high prices in the collector’s market.

Pineapple Opals: Rare Pseudomorphs from White Cliffs, Australia Photo: Grant Pearson

How They Form

Pineapple opals are pseudomorphs—minerals that have replaced another mineral while preserving the original crystal shape. In this case, opal replaces the mineral ikaite (a hydrated form of calcium carbonate: CaCO₃·6H₂O).

• Ikaite forms only under specific conditions—low temperatures, high alkalinity, and elevated pressures—typically in deep marine or cold sedimentary environments.
• Over time, as environmental conditions shift, the unstable ikaite decomposes and is replaced molecule by molecule by silica-rich fluids, forming opal.
• The original crystal habit of ikaite, which features radiating spear-like formations, is preserved—resulting in the iconic spiky “pineapple” shape.

Ananas Opal

The terms “pineapple opal” and “ananas opal” are used interchangeably. "Ananas" is the Latin (and international) word for pineapple and is often used in the gem trade to describe this specific opal morphology. The word "ananas" is the Latin word for "pineapple," hence the association with the opal's texture.

Pineapple Opals: Rare Pseudomorphs from White Cliffs, Australia. Photo: RedEarthOpal

Pineapple Opal Price & Value

Pineapple opals are one of the rarest gemstones in the world, and their price reflects that. Prices can range anywhere from $1,000 to $500,000, depending on the size, quality, and rarity of the specimen.

The most expensive pineapple opals are those that are large and have a vibrant display of colors. These opals are often cut into cabochons or other shapes that showcase their unique appearance.

Opal Pineapple specimen. Photo: RedEarthOpal

Physical Characteristics

Size: Typically palm-sized (2–7 cm).

Color Range: Most often blue, green, or yellow, though other hues can occur.

Transparency & Luster: Often translucent with a waxy to vitreous sheen.

Play-of-Color: Some specimens exhibit flashes of spectral colors as light diffracts through ordered silica spheres.

he Heart of Australia, a 3,510 ct double pseudomorph ikaite-calcite-opal gem specimen, is considered one of the finest ever unearthed. (Pineapple Opal Fossil) Courtesy of Graeme Dowton.

Facts about Opal Pineapples

• They are a type of pseudomorph, which means that they have replaced another mineral.
• The original mineral that was replaced by opal was ikaite, which is an extinct mineral.
• Ikaite crystals can only form in very cold water, so Opal Pineapples are found in the White Cliffs region, which is one of the coldest places in Australia.
• Opal Pineapples are typically small, but they can grow up to 10 centimeters in diameter.
• They are very rare, and only a few hundred have ever been found.
• Opal Pineapples are highly prized by collectors, and they can sell for thousands of dollars.

Pineapple opal is a rare pseudomorphic gemstone formed by the opalization of ikaite crystals within marine sediments of the White Cliffs region. Its unusual morphology, geological significance, and limited availability make it one of the most distinctive and collectible opal types in the world.