Your Purchases
Absorbent opal is a hydrophilic variety of opal mineral characterized by its unique ability to absorb and retain water, containing up to 20% water by weight within its amorphous silica structure. This mineraloid, discovered in volcanic deposits, exhibits a distinctive porous network of microscopic channels that facilitate fluid absorption and retention.
The mineral’s internal structure consists of tightly packed spheres of silica surrounded by interconnected void spaces, creating a natural molecular sieve. These voids, ranging from 0.1 to 0.4 micrometers in diameter, enable the absorption of water molecules through capillary action. The absorbed water content significantly influences the opal’s optical properties, including its transparency and refractive index.
Found predominantly in volcanic regions of Australia, Mexico, and Ethiopia, absorbent opal displays variable colors from white to pale yellow, depending on trace elements and water content. The mineral’s hygroscopic properties make it valuable for scientific research in fluid dynamics and potential applications in moisture-sensitive technologies.
Absorbent opal is typically a natural gemstone.
Common names for Absorbent opal include Diatomaceous earth, Diatomite, Kieselgur, and Kieselguhr.
Absorbent Opal generally has a hardness of about 5.5 to 6.5 on the Mohs scale, which makes it relatively softer compared to many other gemstones. This level of hardness means it is somewhat susceptible to scratches and abrasions, and care should be taken when wearing or setting in jewelry.
The refractive index of Absorbent Opal ranges typically between 1.42 and 1.43. This property affects how much light is bent, or refracted, when entering the stone, influencing the overall brilliance perceived by the eye.
Absorbent Opal has a subvitreous to waxy luster, which contributes to its unique visual appeal. The play of color seen in some opals is due to its luster combined with internal structures.
Opal, including Absorbent Opal, does not have any natural planes of cleavage, meaning it does not split easily along any specific direction when being cut.
This type of opal typically exhibits a conchoidal to uneven fracture, which can be somewhat brittle, making it challenging to cut and polish without the right equipment or expertise.
The specific gravity of Absorbent Opal usually ranges from about 1.98 to 2.25. This measurement indicates the density of the gemstone compared to water.
Absorbent Opal is an isotropic material, which means it has no double refraction. Light passes through the stone uniformly regardless of its direction.
Opal is known for its spectacular play of color, often referred to as “”fire.”” This dispersion varies widely among individual stones and is primarily influenced by the internal structure and composition of the gemstone.
Opal, including Absorbent Opal, is amorphous, meaning it does not have a crystalline structure. This lack of a regular atomic structure contributes to its unique light interactions.
Absorbent Opal can display a wide range of colors, often showing vibrant play of color against a light or dark background. The colors seen depend on the conditions under which the opal formed.
This gemstone varies from completely opaque to translucent. The level of transparency affects the play of color and the overall appearance of the gemstone.
Absorbent Opal does not exhibit pleochroism due to its amorphous nature.
Some opals can show fluorescence under ultraviolet light, typically displaying a white or greenish glow, although this can vary.
Opal is generally considered to have fair to good toughness, but this can depend on the specific structure and water content of the stone.
The tenacity of Absorbent Opal can be described as brittle, necessitating careful handling and setting in jewelry.
Being isotropic, Absorbent Opal does not have an optic sign.
Absorbent Opal does not typically display a characteristic absorption spectrum due to its amorphous nature and unique play of color.
Opal is a hydrous silicon dioxide (SiO2·nH2O), meaning it contains water within its mineral structure, which can affect its physical properties and appearance.
While not common, some opals can exhibit chatoyancy when cut properly, although this is less likely in Absorbent Opal.
Asterism or the star effect is not commonly associated with opal, including Absorbent Opal.
The iridescence in opals is one of their most sought-after features, resulting from the diffraction of light passing through microscopic silica spheres within the stone.
Absorbent Opal is generally not magnetic.
Due to its high water content and amorphous nature, Absorbent Opal is generally a poor conductor of electricity.
Opals, including Absorbent Opal, are not radioactive and are safe to handle and wear in jewelry.
