
The black rectangular object was located in a burial site known as 'The Russian Atlantis' in mountainous Republic of Tuva, for it only appears from under water for few weeks a year.
Archeologists jokingly nicknamed the ancient female Natasha, while her accessory was called 'an iPhone'.
''Natasha's' burial with a Xiongnu-era iPhone remains one of the most interesting at this burial site,' Pavel Leus said in a new publication summarising results of several years of recent archeological expeditions to the Ala-Tey burial site.
In fact, the discovery is a large - 18cm by 9cm - chic belt buckle made of gemstone jet with inlaid decorations of turquoise, carnelian and mother-of-pearl.
The woman's belt was decorated with Chinese wuzhu coins which helped the scientists to date it.
They believe it might be up to 2,137 years old because this is when such coins were first minted.
The find was made in 2016 at the Ala-Tey necropolis in the Sayan Sea.
This is a giant manmade reservoir on the Yenisei River upstream of the Sayano-Shushenskaya Dam, Russia's biggest power plant.
The water drains in May and June each year exposing the vast desert-like floor.
Graves have been found here dating from the Bronze Age to the time of Genghis Khan.

One called 'Sleeping Beauty' - dressed in silk for the afterlife - was at first believed to be a priestess. Now she is thought to have been a leather designer.
The second was a weaver laid to rest with her wooden spindle packed inside a sewing bag.
As many as 110 burials appeared on an island in the reservoir at Ala-Tey site.
'This site is a scientific sensation', said Dr Marina Kilunovskaya from the St Petersburg Institute of Material History Culture, who leads the Tuva Archeological Expedition.
'We are incredibly lucky to have found these burials of rich Hun nomads that were not disturbed by (ancient) grave robbers.'
Pavel Leus is from the Society for the Exploration of EurAsia.
Tuva archeological rescue expedition in flooded areas is possible thank to a grant from the Russian Geographical Society, and help from Society for the Exploration of EurAsia (Switzerland).















Comment: That is one impressive piece of craftsmanship. Jet (lignite) is soft enough to be cut and polished to either a matt or luster finish, but that thing still looks like it was machined!