Sodium chromite pyroxene: sodium chromite pyroxene jade is the main source of emerald green colormineralA small amount of omphacite is distributed in the sodium chromite pyroxene, with the content of more than 95%.
The crystal of sodium chromite pyroxene jade is a microscopic columnar aggregate. Due to the wavy extinction characteristics of stress, it often appears as metamorphic crystal.The grain size is generally 0.1 × 0.01mm, and some can reach 0.5 × 0.1mm. The cylindrical surface is developed, and the cleavage {110} is clear.
Refractive index Nm=1.740,Np=1.725，Ng=1.745。
The polychrome of sodium chromite pyroxene is very significant, with polychrome Nm=light green yellow, Np=light green, and Ng=emerald green.
The English name is ureyite clinopyroxene group mineral gem.The chemical formula is nacrsi2o6.This mineral is a rare jewel in nature. It was first found in lunar minerals.Later, it was found in the jadeite rock of Myanmar.It is one of the main material components of the so-called dry green species in jadeite.It is light green dark green with an average refractive index of 1.75.Hardness 5.
Study on jadeite jade by EPMA, X-ray diffraction and absorption spectrum analysisSodium chromite pyroxeneThe mineralogical characteristics of.The results show that sodium chromite pyroxene andEmeraldIt has a symbiotic relationship, its molecular formula is (Na0.83Ca0.02) (Cr0.78Al0.10Fe0.08Mg0.02) Si2.06O6, its cell parameter is a=9.530 (A), b=8.672 (A), c=5.264 (A), β=107.51 °, V=414.88, and its density is 3.55 g/cm3. The crystal field transition of Cr3+in sodium chromite pyroxene determines that it has different green tones in depth.
