DIMAPUR, Dec 3: It’s official now. The crystal stones found at Wanching village in Mon district of Nagaland by the locals and presumed to be diamond turned out to be quartz. The four-member team of geologists who were sent by the state geology and mining department confirmed that the stones found in the village last week were actually quartz.
Geologists Abenthung Lotha, Longrikaba, Kenyelo Rengma and David Lhoupenyi were deputed by the directorate of geology and mining on November 27 to investigate the occurrence of the mineral after the news of its finding was circulated on social media.
The team has identified the said mineral crystals circulated on social media as quartz crystals which are found abundantly in the sedimentary rocks of Nagaland along veins, fractures, faults etc. The gem quality of quartz crystals are determined from its optical and physical properties such as refractive index, colour, hardness etc.
The geologists told this correspondent that real diamond cannot be scratched and cut by any other metal other than the diamond itself, is transparent and colourless while the stones that were found in Wanching village could be scratched, is brittle and not transparent. From these preliminary tests, they could ensure that these stones were not diamond of any kind.
They said some buyers from Assam bought the shining stones from some Wanching villagers at a rate ranging from Rs 20,000 to Rs 1 lakh per stone after the news of discovery of the minerals went viral. They wondered why the stones were bought without being verified to be stones.
“Maybe they were purchased for therapeutic or religious purposes,” geologist Lhoupenyi said.
Director of geology and mining S. Manen, in a release, said the said mineral crystals found in Wanching village occur in the veins/fractures of sedimentary rocks of Disang-Barail Groups. It is spread over a shallow depth and may be formed due to silicification of crystals along the fractures of sedimentary rocks formed at few kilometres depth and less than 100 million of years.
However, in the case of diamond, crystals are formed in igneous rocks known as kimberlite and lamproites. They are formed under extremely high pressure and temperature, at a depth ranging from 150 km and 250km and older than a billion years, he said.
Mamen clarified that diamond crystals of that size speculated on social media cannot occur or be found in sedimentary rocks, except in rare cases of transportation by natural agents as fine grains or micro-diamonds.