Wednesday, 22 March 2017

Red Beryl

Red beryl is an extremely rare variety of beryl that receives its red color from trace amounts of manganese. World-wide, crystals suitable for cutting gems have been found in one location only, the Ruby-Violet claims in the Wah Wah Mountains of Beaver County, Utah. The Utah Geological Survey estimated that one crystal of red beryl is found for every 150,000 gem-quality diamonds.

Red beryl is extremely rare because its formation requires a unique geochemical environment. First, the element beryllium must be present in large enough amounts to form minerals. Second, dissolved manganese must also be present at the same time and location. Third, the correct geochemical conditions must be present for beryllium, manganese, aluminum, silicon, and oxygen to crystallize into red beryl. Fractures and cavities must also be available to serve as a space for the crystals to grow.

At the Ruby-Violet mine, the topaz rhyolite is a lava flow that erupted from volcanic vents about 18 to 20 million years ago. As the lava flow cooled, fractures and cavities developed in the rock. These openings allowed superheated beryllium-rich water and gases to enter the formation. These were released from a magma chamber that was degassing below.

At the same time, surface water was entering fractures above and moving downwards. It carried oxygen, manganese, aluminum, and silicon leached from the rocks above.
Superheated water and gases from below encountered cool waters from above, which produced a change in geochemical conditions that triggered mineral crystallization.

Red beryl rough is rarely larger than one carat and most faceted red beryls are 0.2 carat or less. Most specimens of red beryl from Ruby-Violet have a rich saturated red color. This allows tiny faceted stones to exhibit a vivid red color.
Lab-created red beryl was first produced in Russia by the hydrothermal process in the mid-1990s. As of January 2016, the lab was no longer producing red beryl. Lab-created red beryl has the same composition and physical properties as natural red beryl but gemologists familiar with the materials are able to distinguish lab-created from natural.

The name "red emerald" is sometimes used when referring to red beryl. This name is a misnomer because emerald, by definition, is green.

Famous Diamonds VI

The Blue Empress is a spectacular 14 carat, symmetrical pear-shaped, fancy vivid blue diamond.

The stone was mined at the Premier Diamond Mine in South Africa and was purchased from De Beers by the Steinmetz Group. It was first offered for sale by London’s Harrods in 2003 for £10 million.
The 67.50-carat, cushion-cut Black Orlov is named black but is the colour of gun metal. Like the story behind the famous Hope diamond, legend has it that the Black Orlov was an uncut black stone of 195 carats, pried out of the eye (forehead) of the statute of the sacred Hindu God Brahma from a temple in Southern India.

The diamond turned up in Russia, where it was bought by Princess Nadia Vyegin Orlov.

The Black Orlov was purchased in 1947 by Charles F Winson who sold it to an unknown buyer in 1969 for $300,000.
The Paragon Diamond is one of the more unusually shaped diamonds. It is a 7 sided diamond of 137.82 carats and is rated a flawless D in color. The necklace currently belongs to the Graff Company and is set in combination necklace - bracelet setting.

The gem was mined in Brazil.
The Donnersmarck Diamonds are two yellow diamonds, named after their one time owner Henckel von Donnersmarc. One, a baguette-shaped diamond weighing 102.54 carats, was sold for $3.246 million.

The second, tear drop in shape and weighing 82.48 carats, was sold for $4.666 million.
The Sun-Drop Diamond at 110 carats is the world’s largest yellow diamond. It sold at auction for $10.91m in 2011.

It was found in South Africa in 2010. The stone was cut as a Pear Brilliant, also called Drop Cut.
The Kazanjian Red Diamond is an 5.05-carat red gem on temporary display in the Morgan Memorial Hall of Gems. Red diamonds are the rarest among colored diamonds. Only three 5-carat red diamonds are known to exist: the Kazanjian Red diamond, the trilliant-cut 5.11-carat Moussaieff Red, and the 5.03-carat De Young Red.

The original 35-carat piece of rough was discovered in Lichtenburg, South Africa
The Spoonmaker's Diamond is a 86 carat pear-shaped diamond, pride of the Imperial Treasury exhibitions at the Topkapi Palace Museum, Tehran.

Tuesday, 21 March 2017

Mexican Fire Opal

The traditional opal, with its unique play of color, has been valued since ancient times. During the Middle Ages, precious opal was regarded as lucky because it displayed the colors of many different gemstones. Not every culture has had the same views. A well-known Russian superstition associates precious opal with the evil eye.

Fire opal is an opal known not for its play of color, but for its vivid body color, which ranges from white to yellow to orange to red.
Like all opals, the fire opal is amorphous hydrated silicon dioxide. "Amorphous" indicates that opal has no crystalline structure; "hydrated" means that it contains water, typically from 3 to 10%. Fire opal has some unusual characteristics not shared by other opals. Opal is typically opaque and is cut en cabochon. Fire opal is the only opal that can be transparent to translucent with higher-grade material cut in facets.
People seeing these gems for the first time are often surprised to find out that they are opals.

Fire opal is associated especially with Mexico, and is mined in the Mexican states of Queretaro, Hidalgo, Guerrero, Michoacan, Julisio, Chihuahua and San Luis Potosi.

The most important mines in Queretaro were discovered in 1835 and are still producing today. Small quantities of fire opal can also be found in Oregon and British Columbia.

The Marcial de Gomar Collection - Update

“La Gloria”, a rough emerald weighing 887 carats, will be a leading lot at the Guernsey’s auction in New York on April 25th. Est $ 4 - $5m

Other rough and cut emeralds will also be auctioned, including the “Marcial de Gomar Star”, which Guernsey’s has described as “the largest recorded star emerald and one of only 11 in the world”.
Estimate $2-3 million
In addition to gold and silver coins salvaged from the Atocha wreck, the Guernsey's sale features spectacular jewelry, such as the Corona de Muzo, which includes a 24.34-carat emerald from the wreck, combined with smaller emeralds and diamonds (estimate $5-6 million).
Conquistadora, crafted of 889 diamonds and 35 emeralds, which can be worn both as a necklace and as a tiara (estimate $150,000 to $250,000).

Monday, 20 March 2017

Treasures From Atocha at Auction

A gold chalice from the Margarita was the top selling lot, fetching $413,000.
A collection of shipwrecked 17th and 18th century Spanish treasure discovered off the coast of Florida has sold in New York in 2015 for about $2m.

US treasure hunter Mel Fisher was most famous for discovering the shipwrecked Spanish galleon Nuestra Senora de Atocha, which went down in a hurricane in 1622, laden with new world riches.

A gold crucifix with inlaid Colombian emerald jewels sold for $119,000.
After searching for some 16 years, treasure hunter Mel Fisher unearthed the treasures of Atocha near the Florida Keys in 1985. 40 items from the impressive cache went up for auction in New York City on August 5, 2015.

A gold bar from the Atocha made $93,750.

The golden spoon was thought to be used by priests during Communion to convert South American natives. $62,000.

The haul includes two spectacular gold chains, one called a 'money chain'. Fisher wore it on the 'Tonight Show Starring Johnny Carson' soon after the ship's discovery.

In the Colonial era, the Spanish king placed a 20 percent tariff on gold bullion called the Royal Fifth. But if the gold was turned into jewelry, the tax was forgiven. Each link of the 'money chain' is of equal size and weight and could be twisted off and used as formal currency.
Also up for auction is a Bezoar Stone, which was believed to remove poisons and toxins from liquids. The pendant, about the size of an egg, is encased in a gold mounting with four arms grasping the stone.
A magnificent emerald jewel from the lost Atocha. It made $ 410,000 in 2013

The Guernsey's sale also offered about 100 silver coins from the Atocha sister ship, the Santa Margarita, ranging from $1,000 and up.