Monday, 17 December 2018

December Birthstone - Tanzanite

20 years ago the Mirerani quarries, located in Simanjiro District of Manyara Region used to produce large amounts of tanzanite. Tanzanite production has been drastically dropping, and like every other single source gemstone ever known the deposit is being depleted.

Its called a single-generation stone.
There seems to be no end in demand as it has become a favorite of many fashion forward jewelry designers. It has become popular as an engagement stone, and in China, the driver for many gemstone prices.

The price of high quality material has started to rise as the Tanzanian government attempts to stop smuggling out of the mining area and the country. Much of the rough was smuggled into neighboring Kenya and exported mostly to India for cutting.
The current price and value for tanzanite changes based on weight. Tanzanite showing a noticeable green component will be worth much less. For richly colored AAA tanzanite, 1ct is about $300-$425 per carat. 2ct sizes reach $450-$650 per carat. 3 carats and up will reach $650-$750 per carat.

Tanzanite in the highest grades is a very good investment stone.

Sunday, 16 December 2018

Chrome tourmaline

Chrome tourmaline is a special member of the tourmaline group.

Found only in east Africa, it is usually found in small sizes. What it lacks in size it makes up for in color - it displays perhaps the richest, most intense green in the gemstone world.
There are similarities between chrome tourmaline and tsavorite garnet. They are found in the same locations in Tanzania, and both are colored by chromium and vanadium. Chrome tourmaline, in many ways, is equal to the finest tsavorite. Chrome tourmaline is a distinct variety of tourmaline, called chrome dravite.
Like emerald and tsavorite garnet, fine chrome tourmaline is a pure forest green with slightly yellowish to bluish secondary hues. With a hardness of 7 to 7.5 on the Mohs scale and no cleavage, tourmaline of all types have good durability.

Generally, tourmalines are Type II clarity stones, showing inclusions. However, one can find eye clean green chrome tourmalines. Most would only buy chrome tourmaline graded IF (internally flawless) to VS (very small inclusions).

Saturday, 15 December 2018

Tritium

Tritium is used as a radioactive tracer, in radioluminescent light sources for watches and instruments, and as a fuel for nuclear fusion reactions.Tritium is a radioactive isotope of hydrogen. Naturally occurring tritium is extremely rare on Earth, where trace amounts are formed by the interaction of the atmosphere with cosmic rays. It can be produced by irradiating lithium in a nuclear reactor.
Tritium presents no radiation threat when encapsulated properly. Tritium is used today in glow-in-the-dark lighting for signs and is trending as key ring accessories.
Tritium tubes are gas-filled, thin glass vials with inner surfaces coated with a phosphor. The gaseous tritium in these light sources undergoes beta decay, releasing electrons that cause the phosphor layer to fluoresce. Tritium radiation cannot penetrate intact human skin.

Light sources can glow for ten years or more without needing any kind of charging.

Friday, 14 December 2018

552 carat yellow diamond found at Diavik

The biggest diamond ever found in North America has been unearthed by Dominion Diamond Mines and Rio Tinto Group.

The 552-carat yellow gem quality stone was found at the Diavik mine and is among the 30 largest diamonds ever unearthed.

Thursday, 13 December 2018

Pantone Color of the Year 2019 - Living Coral

To gem lovers 'living coral' can only mean the rare and beautiful Padparadscha sapphire.
See ----->Padparadscha Sapphires

Alisa Moussaieff

Alisa Moussaieff knows gems. It’s been more than 50 years since she and her late husband, Shlomo, opened their first boutique on Park Lane in London. The family jeweler has been supplying exceptional gemstones and high jewelry around the world ever since.

At 89 years old, Mrs. Moussaieff isn't slowing down. The company debuted it's latest collection at the La Biennale Paris, September 11th.

Chameleon diamond

Tuesday, 11 December 2018

Sinatra auction fetches $9.2m in New York

A Frank Sinatra auction in New York, where items owned by the late icon and his fourth wife were offered, fetched $9.2 million. 99% of the lots were snapped up, attracting 300 bidders from more than 30 countries.

Many of the items fetched far more than their pre-sale estimates.
Top lot was Barbara Sinatra's 20-carat diamond engagement ring which made $1.7m. A Norman Rockwell portrait of Sinatra, which he commissioned, sold for $687k and a script for "From Here to Eternity," the movie for which he won an Oscar, went for $35k.

Monday, 10 December 2018

8.08-carat Fancy Blue leads Christie’s NY Magnificent Jewels

Fancy colored diamonds and big names led Christie’s auction of Magnificent Jewels in New York. The top lot in the sale was an 8.08-carat, cushion-cut, fancy vivid blue diamond by Bvlgari.

The final price was $18,312,500, topping it's high estimate. A 15.56-carat heart-shaped pink diamond, set in a pendant, sold for $9,537,500.
Christie’s sold a pair of earrings weighing a combined 77.71 carats from the 187.7-carat Diavik Foxfire, North America’s largest gem-quality rough diamond. Price when the hammer came down was $1,572,500.

An 8.09-carat oval shaped, internally flawless yellow diamond ring made in 1925 by Gillot & Co. sold for $1,308,500.


A Belle Époque ring (circa 1915) with a 6.28-carat Kasmir sapphire sold for $936,500.

An Art Deco aquamarine and diamond tiara-style necklace made by Cartier in 1935 sold for $828,500 blowing past it's estimate of $70,000-$100,000

Sunday, 9 December 2018

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 about 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.