The Black Orlov diamond - the Hindu temple from where it was stolen is subject to further research

Orlov diamond and Imperial Scepter of Russia tripod.com,

Above image: Russian royal  Scepter commissioned by empress Catherine the Great. A burnished shaft,  the scepter has  three sections set with eight rings of brilliant-cut diamonds, including some of about 30 carats (6 g) each and fifteen weighing about 14 carats (2.8 g) each. The Orlov is set at the top.  Note the dome shaped gem facing outward A  double-headed eagle with the Arms of Russia enameled on its breast.

Black Orlov diamond of India origin, in.pinterest.com

For the extremely rich people, possessing a well-known historical diamond is more a status symbol matching their vanity  pride and affluence than anything else. The rich diamond - black Orlov or 'Eye of Brahma' is as famous for its astonishing beauty and brilliance as for the curse it carries and its mysterious origin in  Hindu temples. But it is marked out as an  extraordinary gemstone  on the rich tapestry of human history. 

Orlov diamond stolen from Srirangam  temple, India. imgarcade.com

A perusal of several articles on the famous  cursed Orlov diamond of India origin suggests that the diamond once adorned the eyes of the  Hindu god Brahma  in a temple in Pondicherry (South India),  once a famous French colony. It was stolen by a French soldier  from the  temple. Some articles point out that a greedy Hindu monk stole the diamond and sold it to an Englishman in Chennai. The details of the  temple in the old French colony are sketchy. Positively the temple from where the Orlov was stolen is not dedicated to god Brahma. The idol could have been mostly removed from  the Trinity god Shiva or Vishnu. There are many conflicting reports on the Hindu temple and its deity that was adorned with this classic diamond.  . 

Incidentally, because of a curse cast by god Shiva on god Brahma, there are very few Brahma temples in India mostly in northern states. The famous one being in Pushkar in Rajasthan. There are small Brahma temples in Tamil Nadu near Trichy city and Kumbakonam and they are not famous.  As far as I know there is no such Brahma temple in Pondicherry and as such,  I don't know how this misinformation creates a link between Brahma temple and  the Orlov diamond. 

Srirangam Vishnu temple, 1000 pillar hall, TN,  Flickr

 Some theories link Orlov diamond with the Srirangam  Ranganathar temple of  Tamil Nadu which is the 3rd largest functional Hindu temple in the world.  Believed to have been in the jewelry worn by the main  deity (Sri Vishnu), it is said it was stolen by a French soldier,  deserter  from the  Angelo-Carnatic  war  that was fought  between  the French  forces  led by  Dupleix and  Nawob Chanda Sahib on one side,  and the British force  on the other side, for the first time led by Robert Clive  of  the East  India  company. Robert Clive emerged victorious  and won the appreciation of the English company  along with  promotion.

The priests at Srirangam  allowed Hindu convert  to access the sanctum as the French man  had been there for sometime, proving his loyalty to the god.  Knowing the value of the diamond, at the right opportune moment, he stole the diamond and fled to Madras where he  is said to have sold it to an English sailor for a fat price. Grief stricken  over  the stolen diamond from the deity, the temple  priests  cast a curse on the gemstone......... ''Whoever owns and wears this God's diamond will  experience untold  misery  and pain  till the world lasts.'' 

In its  chequered  history, the diamond  passed on to  many hands and finally ended in the Russian royal scepter.  

Russian empress Catherine the great. famousdiamonds.tripod.com

This Orlov diamond of Kollur origin (present day Andhra state) is one of the largest diamonds in the world and  weighs 189.62 karat. It is said to have been given to Catherine the Great by her lover, a  Russian nobleman and army officer  Count  Gregory Orlov (1723-83),   Incidentally, in the 18th century,  Russia was primarily headed by woman rulers and it is said that  during Catherine's reign  the Russian court became the  proud owner  of many famous diamonds and  obviously, the Orlov Diamond in 1774 became part of the royal scepter.  The other story is the empress who was fond of gem stones bought the diamond  with money from the royal state's  exchequer. The diamond survived many political upheavals and storms, finding a home in Moscow’s Kremlin Diamond Fund, where it is showcased in the esteemed Jewels of the Crown exhibition. 

.bloglovin.com/

Many Hindu gemologists are skeptical about the temple where it was stolen. Hindus always shun black color, as it is associated with witchcraft or sorcery.  Like Koh-i-Noor diamond,  the Black Orlov diamond has a bizarre and enigmatic history  with many twists and turns  that are veiled in secrecy. Though  the enigma surrounding the  Hindu temple still persists,  its craftsmanship and the timeless allure of exceptional gemstones still baffle us. 

https://www.naturaldiamonds.com/rare/the-unbelievable-story-of-the-black-orlov-a-cursed-diamond

 https://adastrajewelry.com/blog/the-enchanting-tale-of-the-orlov-diamond-or-the-great-mughal-diamond

https://medium.com/@adastra.worldwide/the-enchanting-tale-of-the-orlov-diamond-1bfc7cc255d7