The Idol's Eye is a 70.21-carat diamond reportedly valued at more than $27 million, thought to be the world's largest cut blue diamond.
It is just 2.6cm long and 2.45cm wide.
This week, however, the tiny, pale blue stone made headlines around the world as the subject of a bitter court battle between two branches of Qatar's royal family.
For a diamond found in 1600 and passed through the hands of royals, art collectors, sultans and aristocracy, there was a single question that needed to be answered.
Was The Idol's Eye for sale?
The 'limpid' diamond discovered in an Indian mine
When it comes to diamonds, there are few more prized than those hacked from mines near the Golconda fort in India.
The Hope Diamond, the Regent Diamond, the Kohinoor — and, yes, The Idol's Eye — were excavated from the area's mine.
According to Christie's auction house, the ruined city near Hyderabad was once the "bustling centre" of the world's diamond industry.
[youtube]"'Golconda' is a name used within the jewellery world to denote the world's finest diamonds," it wrote.
"[These are] gems that possess superb luminousness, transparency and an innate purity."
Golconda diamonds, according to Christie's, have a higher degree of transparency — the light "appears to pass through the stone as if it were totally unimpeded".
By the 17th century, the diamond industry was booming.
And it was at this point, with tens of thousands of workers on the hunt for the precious stones, that The Idol's Eye was first discovered.
Though there is little evidence to back it up, the diamond is surrounded by stories of idol worship, theft, kidnapping and debt collection, according to the Antique Jewelry University.
The Idol's Eye was said to have been owned by a Persian prince before being seized as payment for debts. Following this unsubstantiated story, it reportedly disappeared for almost 300 years.
Its first authenticated appearance was in a Christie's London saleroom in 1865.
From there, it went to the 34th Ottoman Sultan, Abd al-Hamid II, until he was overthrown, according to Christie's.
"In an attempt to dispatch his jewels to safety, The Idol's Eye was stolen by the servant entrusted with it," the auction house said.
The diamond went on to auction in Paris, then to a Spanish nobleman, then to the "King of Diamonds" Harry Winston in 1946.
Set in the middle of 152 diamonds on a necklace and passing through several more hands over the following decades, it was acquired by Sheikh Saud bin Mohammed Ali Al-Thani sometime after 2001.
And that is where our legal battle starts to unfold.
The son, the daughter and the Swiss lawyer
Shiekh Saud — Qatari prince, minister of culture, arts and heritage, and avid art collector — loaned the diamond to his second cousin once removed in early 2014.
The cousin, Sheikh Hamad bin Abdullah Al Thani, is the chief executive of private investment company Qipco Holdings.
Elanus Holdings, a company linked to Shiekh Saud, loaned Qipco the diamond for 20 years.
If Elanus wanted to sell, Qipco had the right to buy The Idol's Eye for either $US10 million ($15.81 million), or the average estimated value given by two major auction houses.
At the end of 2014, Shiekh Saud died.
His family went back and forth over potentially selling the stone to settle debts but, according to documents from London's High Court, the discussion "fizzled out".
His son, Sheikh Hamad bin Saud Al-Thani, again returned to potentially selling the diamond in early 2020.
"[I] thought that if I found something that might excite me and my family, they might be persuaded to consider a sale of The Idol's Eye to fund the purchase of new assets," he told the court.
Dieter Neupert, a Swiss-based lawyer, was asked to provide a contract for the sale.
Dr Neupert notified Qipco the family wished to sell The Idol's Eye in February 2020, court documents said.
Sheikh Saud's daughter, Sheikha Sara bint Saoud Al-Thani, said the first time she heard of the proposed sale was in March.
"She said she was shocked on learning about it," High Court Deputy Judge Simon Birt said in his findings.
"She told [her mother] who said … the family had never discussed selling the diamond and she would never agree to or be happy with its sale."
Dr Neupert contacted Qipco to back out.
The "present crisis" of the COVID-19 pandemic, he told the company, meant there was no market for diamonds, and no valuation available.
The family would not sell.
High Court weighs in on 'wish' to sell The Idol's Eye
Meanwhile, Qipco had been in contact with Christie's in order to get the auction house's formal valuation — it ultimately supplied an estimated auction value of $US7-10 million.
It told Elanus to provide its own valuation so the sale could move forward.
The matter landed in London's High Court, where an eight-day trial played out over November last year.
Elanus argued the Swiss lawyer was not acting on the organisation's behalf — and, regardless, it had withdrawn any "wish" to sell.
"Moreover, it is clear … even if there had been [a] 'wish' on the part of [Sheikh Saud's son] to sell the diamond which could be attributed to Elanus, there was … no longer any such wish [by April]," Judge Birt said.
"Once Sheikha Sara had discovered the fact that there was a proposal to sell the diamond, and she had in turn informed Sheikha Amna, it is clear that they were both upset at the situation.
"Sheikha Amna because she did not want it sold at all, and Sheikha Sara mainly because of the steps [her brother] had taken without any consultation with the rest of the family.
"They both made their feelings very clear."
The High Court finally dismissed the case on Thursday, local time — Elanus could not be made to sell The Idol's Eye.