The most important mineral component is lazurite, a feldspathoid silicate mineral. It also contains calcite, sodalite, and pyrite. Some samples of lapis lazuli contain augite, diopside, enstatite, mica, hauynite, hornblende, nosean, and sulfur-rich lollingite geyerite.
Lapis lazuli usually occurs in crystalline marble as a result of contact metamorphism.
The intense blue color is due to the presence of the trisulfur radical anion in the crystal. An electronic excitation of one electron from the highest doubly filled molecular orbital into the lowest singly occupied orbital
We find Lapis lazuli in limestone in the Kokcha River. A valley of Badakhshan province in northeastern Afghanistan. Where the Sar-e-Sang mine deposits are open for more than 6,000 years. Afghanistan was the source of lapis for the ancient Egyptian. And Mesopotamian civilizations, as well as the later Greeks and Romans. Ancient Egyptians obtained this material through trade from Afghanistan with the Aryans. During the height of the Indus Valley Civilisation about 2000 BC. The Harappan colony (Shortugai) was established near the lapis mines.
According to the Sorbonne’s mineralogist Pierre Bariand’s. Leading work on the sources in modern times. And to references in Afghanistan’s Blue Treasure: Lapis Lazuli (2011) by Lailee McNair Bakhtiar. It is found in “caves”, not in traditional “mines”. And the stone lapis lazuli is from the primary source of the Hindu Kush Mountains. In Afghanistan’s Kochka River Valley.
In addition to the Afghan deposits, we found lapis in the Andes. Near Ovalle, Chile, and to the west of Lake Baikal in Siberia, Russia, at the Tultui Lazurite deposit. Smaller quantities are also avalaible in Angola, Argentina, Burma, Pakistan, Canada, Italy, India, and in the United States in California and Colorado.
Uses and substitutes
Lapis takes an excellent polish. We can use it in jewelry, also carvings, boxes, mosaics, ornaments, small statues, and vases. During the Renaissance, Lapis was ground and processed to make the pigment ultramarine. For use in frescoes and oil painting. Its usage as a pigment in oil paint largely ended in the early 19th century. When a chemically identical synthetic variety became available.