What is Jadeite?
The Jade word comes from the Spanish becuase of it curing ailments of the lions and kidneys. Jadeite is the name of the mineral. It generally comes in a big green rock and the formula of Jadeite is (NaAlSi2O6). When we see it from microscope it shows mixed texture of granular and ibrous polycrystalline aggregates.
The Most valuable variety of Jade is called Imperial Jadeite. Imperial Jadeite have intense green color in it. Majority of the Jadeite Jade extracted from the classic Uru river area (Kyaukseinmyo) in northern Myanmar. Most of the Jadeite crystals have dark elongate inclusion in their core.
History of Omphacite Jade?
The story of Omphacite Jade started when a green cabochon submitted to the Carlsbad laboratory in the year 2012. Everybody questioned the identity of this green cabochon even after it tested as Jadeite. The main reason of questioned was because of its different structure than the Jadeite. A group of gemologists perform a Raman spectrum experiment which confirms that it didn’t match with the Jadeite.
This experiment not only confirms but also make us wonder how many Omphacite Jade stones were used and tested as Jadeite. After this incident, every piece of Jade stones started to test for actual identification.
Most of the stones tested was actually Omphacite but their colors, RI, SG, Texture and appearance were similar to Jade. After finding a new stones, gemologists started finding a name for it and then they gave it a name “omphacite” based on their mineralogical name.
Difference Between Jadeite & Omphacite Jade?
Jade was first discover around 1863 in Damour. Jadeite and Omphacite jade belongs to the same mineral family called pyroxenes. This pyroxenes form a series of solid solution. The members of this series have different chemical changes and different structure. The chemical formula for Jadeite is NaAlSi2O6 and for Omphacite Jade is (Ca,Na)(Mg,Fe2+,Al)Si2O6. Omphacite is the name of the mineral and composed of the same mineral.
Omphacite is found to be chemically more complex than the Jadeite. Both Jadeite and Omphacite have different crystal structure due to difference in pressure and temperature. Jadeite belongs to one group (C2/c) while Omphacite belongs to three polymorphs with symmetry C2/c, P2/n and P2.
The Jadeite show complex composition association with sodic and sodic-calcic amphiboles while Omphacite shows monomineralic composition. Omphacite is less transparent when compared to Jadeite while transmitted light appears to be greyish green.
How to Identify Omphacite Jade Mineral?
Omphacite Jade is known with many names like Mo Cui or Mexican green or Inky Jade or Black Jadeite. With our naked eyes, it’s hard to find the difference because Omphacite Jade and Jadeite appear too much similar. It can only be confirm in the laboratory by expert gemologists by using the Raman spectra analysis.
As we have seen above Jadeite and Omphacite Jade is slighlty similiar to each other but at the same very far different to each other. Both the minerals are used for making jewelry and decorative items.