115 carat diamond leads at Christies New York

Top lot at Christie’s Magnificent Jewels sale was a 115.8-carat pear-shaped, F color, VVS1 diamond on a diamond necklace. It sold for $6.29m. Anna Hu's "Sky Tower" jadeite necklace was withdrawn from the auction. Its estimate was $1m to $1.5m.

Number two lot was a 7.16-carat IF, fancy intense blue, pear modified brilliant-cut diamond on a platinum ring that made $3.85m.

The Patiala Necklace

De Beers Consolidated Mines Limited produced a 428 carat light yellow octahedral diamond in March 1888. With a finished weight of 234.65 carats, the cushion cut "De Beers" is the seventh largest faceted diamond in the world. The Maharaja, Bhupinder Singh, of Patiala in the Punjab region of India, bought the gemstone in 1889. In 1925, the Maharaja commissioned Cartier to set the De Beers diamond as the centerpiece of a ceremonial necklace that became known as the Patiala Necklace. In its original form, the necklace was 962 carats contained in 2,930 diamonds and other precious stones. It was completed in 1928 and is one of the most spectactular and expensive pieces of jewellery ever made.

The last sighting of the complete necklace was in 1946 when it was worn by the son of Maharaja Bhupinder Singh, Maharaja Yadavinder Singh. Fifty two years later the necklace was discovered in a second-hand jewellery shop in London by a Cartier representative. All the big stones in the necklace, which included the De Beers diamond and the seven other big diamonds ranging from 18 to 73 carats, and the rubies had all been disposed of. The remnants of the Patiala Necklace was bought by Cartier. It took four years to restore the necklace to it's former glory. On May 6th, 1982 the 'De Beers' diamond came up for auction at Sotheby's in Geneva. The top bid of $3.16 million remained below the undisclosed reserve price.

The necklace was displayed by Cartier across the world to rave reviews. The New York Times wrote gushingly “The crowds are lining up in front of Cartier on Fifth Avenue and 52nd Street, but they are not your average New York Christmas shoppers. They are passers-by staring, aghast, at a fabulous piece of antique jewelry. It’s not even for sale. Nor was it made to satisfy a beautiful woman. It is an ornament made to adorn the chest of a man”.

Yowah Opal

Yowah is a small town in outback western Queensland, Australia. Yowah is located 938 kilometres west of Brisbane and 132 kilometres west of Cunnamulla. The 2006 census revealed a population of 142. The town is famous for its opal mining and numerous opal fields that lie around the town as well as the "Yowah Nut" a local type of opal distinctive to the region. The area was first leased in 1883 to settlers and opal mining has been the main activity ever since.

The Yowah field is an occurrence of opal in siliceous ironstone nodules, referred to as Yowah Nuts. These nuts have a spherical or ellipsoidal shape, and show alternate bands of light and dark brown siliceous ironstone. Sometimes a kernel of precious opal occurs, which is the source of the gem. The nuts are found in layers at depths up to 20m in a ferruginous sandstone.

Jewels shine at Christie's Geneva

A fancy blue and white diamond ring by Reza sold for $9.2m against a $8.5m to $12.8m estimate The first diamond is an internally flawless 5.34-carat fancy vivid blue modified brilliant-cut diamond. The second is a 5.37-carat D color, internally flawless Type IIa colorless diamond. Number two lot was a D-color 100.85-carat diamond with a modified shield mixed-cut. It sold for $5.9m.

A 104.04-carat internally flawless, fancy intense yellow modified pear-shaped, brilliant-cut diamond made $2.5m. Top fancy colored gem at the sale was a 29.54-carat octagonal step-cut Colombian emerald, with minor oil treatment, flanked by tapered baguette-cut diamonds. It fetched $1.8m.

Purple pyrope-almandine garnets

In early 2016 purple garnets from East Africa started to appear. The source was Manica Province in central Mozambique. The deposit is located 60 km northeast of Chimoio, near Gorongosa National Park. The area is under the control of the Mozambican National Resistance (RENAMO), an armed rebel group.

What's special about these garnets is the color - an intense purple with red flashes that is called Royal Purple. The Mozambique material has strong color with extreme brilliance. If this wasn't enough, the garnets also display a color change, from grape under daylight to cranberry with magenta flashes under incandescent lighting.

The government of Mozambique has now closed the area to mining making further supply uncertain.

The material with the best color is found in smaller sizes, under 3-4 carats. Since the color saturation is so intense, larger stones are too dark. The highest grade material has come from the Mozambique deposit, with some stones coming from Tanzania. Both display the distinctive color change.

Dior High Jewellery

Christian Dior, (21 January 1905 – 24 October 1957) was a French fashion designer, best known as the founder of one of the world's top fashion houses, which is now owned by Groupe Arnault. Bernard Jean Étienne Arnault is a French business magnate, Chairman and Chief Executive Officer of LVMH, the world's largest luxury goods company. He is the richest person in France, and the 8th richest person in the world according to Forbes. In 2017, his net worth was estimated to be US$51.7b.

The French Crown Jewels

Statuette of Charlemagne on the sceptre of Charles V. Louvre.

The French Crown Jewels comprise the crowns, orb, sceptres, diadems and jewels that symbolized royalty within French aristocracy between 752 and 1825. The set was broken up and most of it sold in 1885 by the Third French Republic. The surviving French Crown Jewels are mainly on display in the Galerie d'Apollon of the Louvre.

Crown of Louis XV, 1722, Louvre.

The Crown of Empress Eugénie

The Crown of Napoleon created in 1804. Louvre.

Among the most famous diamonds preserved in the collection are the Sancy Diamond, the Hortensia pink diamond cut in 1678 for Louis XIV, and the Regent Diamond. The Royal French Blue was transformed into the Hope Diamond which now resides in the Smithsonian.

One of the mysteries of the French Revolution was the fate of Dauphin, the son of Louis XVI and Marie Antoinette and heir to the crown. In 2004 it was confirmed through DNA evidence that the young prince had died of tuberculosis in prison. The heart of the young man claimed by the royalists to be the young Louis XVII had been secretly removed by a doctor just after his death. By comparing the DNA from the heart with DNA taken from strands of hair of Marie Antoinette that had been kept as a memento by royalists, it was possible to establish that the boy who died in prison was indeed the last heir to the French Crown Jewels.

Napoleon's crown for Empress Josephine, now in the Smithsonian. It was originally set with emeralds but was later reset with turquoises in their place.

Empress Marie Louise Ruby and Diamond Coronation Crown, Nitot 1810

Princess Eugenie Brooch