Geological & Scientific Properties | Dianite
Dianite, also known as Siberian Blue Jade or Blue Nephrite, is a relatively rare and distinct variety of jade. It is prized for its deep blue color, which sets it apart from the more common green shades typically associated with jade. Here's an overview of Dianite's geological and scientific properties:
Chemical Composition and Structure:
- Composition: Dianite is primarily composed of nephrite, a form of actinolite belonging to the amphibole group of minerals. Its chemical formula is Ca₂(Mg, Fe)₅Si₈O₂₂(OH)₂.
- Crystal System: Nephrite, the main component of Dianite, crystallizes in the monoclinic crystal system, forming dense, fibrous aggregates.
Physical Properties:
- Color: Dianite is distinguished by its rich blue color, which is a result of iron and titanium impurities within the mineral structure.
- Hardness: It has a hardness of about 5.5 to 6 on the Mohs scale, which is typical for nephrite jade.
- Luster: Dianite exhibits a smooth, waxy to silky luster.
- Transparency: This mineral is typically opaque.
- Cleavage and Fracture: Nephrite jade, including Dianite, has no cleavage and tends to fracture in a splintery manner.
Optical Properties:
- Refractive Index: Nephrite jade has a refractive index in the range of 1.600 to 1.641.
- Birefringence: It exhibits weak birefringence due to its fibrous structure.
Geological Occurrence:
- Formation: Dianite forms under metamorphic conditions, typically in areas where there has been high pressure but relatively low temperature, such as in subduction zones and serpentinized ultramafic rocks.
- Associated Minerals: It can be found associated with other metamorphic minerals and in jadeite deposits.
Major Deposits:
- Dianite is specifically known from the Sayan Mountains in Siberia, Russia. The limited geographical source contributes to its rarity and desirability among collectors and gem enthusiasts.
Dianite's unique and striking blue coloration, along with its jade-like properties, make it a sought-after mineral for collectors and those interested in lapidary arts. It is also valued in various cultures for its aesthetic and presumed metaphysical properties, although these are not supported by scientific evidence.
