The New York'' Indian jewelery'' auction of 2019 fetched millions of dolllars for Indian Golconda diamonds

Golconda Diamond  newindianexpress.com
A perusal of  diamonds put on sale at  the  auction conducted by 253-year-old firm Christie's in New York in  July 2019 and the exhibition titled, Jewels of India: The Nizam's Jewellery Collection  at the National Museum in New Delhi  (February to May, 2019) will reveal lots of fabulous diamonds called  Golconda Diamonds mined in present day Andhra.  The famous light Pink Golconda Diamond, an oval brilliant-cut  of 10.46 carats was one of star attractions. This particular one was unearthed in the mine on alluvial plains of the tributaries of the Krishna river, South India.

The other diamonds at the New York auction included were
“portrait diamonds''  mined near Krishna river; “Extremely shallow, they consist of virtually nothing but two tables separated by a tiny row of girdle facets. They were sometimes used to cover miniature paintings to make the impressive and therefore came to be known as portrait diamonds.

The other highlight of the New York auction was  the ‘The Nizam of Hyderabad Necklace’, made of an antique diamond, emerald and enamel necklace that the Nizams used to wear during parades. “The necklace has eight large diamonds in set, each having an estimated weight of 10.00 to 15.00 carats.Centuries ago diamond cutting industry was  fairly in an advanced stage in India in the Golconda area and  the modified brilliant-cut of these diamonds reflects the advancement of gem-faceting in India.

The costliest diamond under the hammer was the ‘Mirror of Paradise’ ring, a rectangular-cut 52.58-carat diamond. It has a platinum ring, and “flawless clarity”. It is estimated that it would  fetch between $7 mn and $10 mn.

Arcot diamond II economictimes.indiatimes.com
The Golconda  diamond that got the best attention at Christie's, New York was  diamond 'Arcot II' once owned by Queen Charlotte, consort of King of Great Britain George III, a diamond necklace of the Nizams of Hyderabad. The 17-carat Golconda diamond "Arcot II",was owned by  Nawab of Arcot (Tamil Nadu, S. India) that later went to the British royal family. It was sold for a stunning Rs 23.5 crore ($3,375,00).
''Evening Star'',diamond thenewsminute.com
The other coveted diamonds put on auction at Christie’s earlier include the ''Evening Star'', an old-mine pear-shaped cut stone famous for its transparency, one of the salient features of the Golconda diamonds. In the diamond trade, it is widely accepted that all diamonds displaying this special luminescence  are of Indian origin.

 Tit-bits:
The Golconda Diamonds of India  were once mined in a specific geographic area in the present-day Telangana and Andhra Pradesh states of South India. It was during the rule of  Qutb Shahi dynasty (16th century-17th century CE), also known as the "Golconda Sultanate", diamonds from these mines  called Kollur Mine) were taken to the city of Hyderabad to be cut, polished, evaluated and sold. Golconda town, close to Hyderabad  became an important diamond trading center then  and it flourished until the end of the 19th century. In the annals of Diamond History of the world in the by-gone era, the Golconda market was the primary source of the finest and largest diamonds in the world.
Diamond mining in India/en.wikipedia.org

 The name 'Golconda Diamond' became  legendary and mark of quality and includes an array of world' most  famous diamonds such the colorless Koh-i-Noor (Part of royal collection, UK; it is in the Crown), the blue Hope (United States), the pink Daria-i-Noor (Iran), the white Regent (France), the Dresden Green (Germany), and the colorless Orlov (Russia), Nizam (340 carats) and Jacob (India), as well as the now lost diamonds Florentine Yellow, Akbar Shah and Great Mogul (787 carats;1650).

One of the most popular diamond mines Kollur Mine was located near  Guntur in Guntur district, Andhra Pradesh state. There were also other mines around the River Krishna alluvial deposits in South India.
The most intensive mining was done in a 60 km zone along the river bed.  Along with diamonds, the region also became a trade center for metal ware, pearls, spices and textiles. According to The New Indian Express (22 October 2016), "the Hyderabad based historian, Muhammad Safiullah  has mentioned that the ''estimated output from all mines in Golconda was  around 12 million carats" absolutely mind-boggling. According to Manu S. Pillai, (The Hindu, 05 November 2016), Jean-Baptiste Tavernier, world famous  French traveler and jeweler (believed to an expert in gem-quality diamonds claimed to have seen a flat diamond called the Great Table diamond kept in a dungeon in Golconda. Jean de Thévenot and François Bernier were also French traders in 'Golconda Diamonds'.   Tavernier visited the Krishna River mines - mostly open-cast in 1665, and estimated that about 60,000 people were engaged in  diamond mining.
http://www.newindianexpress.com/cities/hyderabad/2019/jun/10/hyderabads-golconda-diamonds-mined-during-qutub-shahi-period-to-fetch-millions-in-us-auction-1988281.html

 https://en.wikipedia.org/wiki/Diamond_mining_in_India
 https://economictimes.indiatimes.com/magazines/panache/royal-auction-17-carat-golconda-diamond-arcot-iisold-for-rs-23-5-crore/articleshow/69869828.cms