Your Purchases
Pineapple opal is a rare variety of common opal exhibiting distinctive yellow-gold to amber coloration with a unique internal structure resembling the geometric pattern of a pineapple’s skin. This silica-based mineraloid, discovered primarily in Mexico’s state of Jalisco, forms through the precipitation of silica-rich solutions in volcanic host rocks.
The distinctive patterning occurs due to microscopic spheres of silica arranged in a systematic, hexagonal formation, creating a three-dimensional optical effect similar to the fruit’s exterior. These opals typically contain 6-10% water content and display a Mohs hardness of 5.5-6.0. The material exhibits no play-of-color, instead showing a subtle chatoyancy when properly cut.
This variety’s formation requires specific geological conditions, including the presence of hydrothermal solutions rich in dissolved silica and precise cooling rates that allow for the systematic arrangement of silica spheres. The resulting gemstone presents a translucent to opaque appearance with a vitreous to waxy luster, making it highly sought after by collectors and lapidaries.
Pineapple opal is typically a natural gemstone.
Common names for Pineapple opal include Pineapple quartz, Ananas quartz, and Honey quartz.
Pineapple opal, like other opals, typically has a hardness of about 5.5 to 6.5 on the Mohs scale. This makes it relatively softer compared to many other gemstones and susceptible to scratches and abrasion.
The refractive index of pineapple opal is generally in the range of 1.37 to 1.47. This is similar to other types of opal.
Pineapple opal exhibits a waxy to dull luster, which is characteristic of common opals that do not display play-of-color.
Opals, including pineapple opal, do not have a true cleavage. They are amorphous, meaning they do not have a defined crystal structure that can split along specific planes.
Pineapple opal has a conchoidal fracture, typical of opal, which results in a smooth, curved surface when the stone is broken.
The specific gravity of pineapple opal is approximately 2.1, which is slightly denser than most other opals due to its unique internal structure.
Being an amorphous mineraloid, pineapple opal does not exhibit double refraction. It is isotropic, meaning it has the same optical properties in all directions.
Pineapple opal generally lacks the fiery dispersion seen in precious opals. The stone is prized more for its unique patterning and structure rather than for color play or fire.
Opal, including pineapple opal, is amorphous and does not have a crystal system. It is composed of silica spheres that are randomly arranged.
The color of pineapple opal ranges from yellow to brown, and it is distinguished by its unique pineapple-like pattern consisting of a yellowish core with brownish specks or lines radiating outward.
Pineapple opal varies from translucent to opaque, which affects its appearance and the visibility of its internal patterns.
Pineapple opal does not exhibit pleochroism due to its amorphous nature and isotropic properties.
This type of opal may show weak to moderate fluorescence under UV light, typically glowing green or white.
Opals, including pineapple opal, have fair to good toughness, but they can be prone to cracking or chipping due to their inherent internal stresses and water content.
The tenacity of pineapple opal is generally brittle, making it sensitive to pressure and impact.
As an isotropic material, pineapple opal shows a single optic sign.
Pineapple opal does not typically display a distinctive absorption spectrum due to its lack of crystalline structure and uniform coloration.
Pineapple opal is primarily composed of silicon dioxide (SiO2) with a variable water content, which can range from 3% to 21%.
Pineapple opal does not generally exhibit chatoyancy, as this effect is more common in crystalline materials with aligned fibrous inclusions.
Asterism is not typically observed in pineapple opal due to its amorphous structure and lack of aligned inclusions necessary to produce a star effect.
Unlike precious opal, pineapple opal does not typically display iridescence or color play. Its appeal lies in its unique internal patterning.
Pineapple opal is not magnetic and shows no reaction to magnetic fields.
As a type of opal, pineapple opal is an insulator and does not conduct electricity.
Pineapple opal is not radioactive and poses no health hazards in this regard.
