Friday, 29 November 2013

Beryl

In geology, beryl is a mineral composed of beryllium aluminium cyclosilicate with the chemical formula Be3Al2(SiO3). Beryls come in a number of varieties including the blue-green aquamarine, yellow-green heliodor, pink morganite, deep green emerald and the extremely rare red beryl. The name comes from the ancient Greek word beryllos describing a blue-green stone the color of the sea.
Emeralds are a form of beryl, showing the deepest and richest green which is caused by trace amounts of chromium and sometimes vanadium. This rare and beautiful stone has been a favorite of royalty and the wealthy throughout history and was worshiped by Incas and Aztecs as a holy stone. Its various legendary attributes include the ability to foretell the future, bring good luck and wealth and protect against illness.

Emeralds in antiquity were mined by the Egyptians and in Austria, as well as Swat in northern Pakistan. A rare type of emerald known as a trapiche emerald is occasionally found in the mines of Colombia. A trapiche emerald exhibits a "star" pattern. It is named for the trapiche, a grinding wheel used to process sugarcane in the region. Colombian emeralds are generally the most prized due to their transparency and fire.
Golden beryl can range in colors from pale yellow to a brilliant gold. Unlike emerald, golden beryl has very few flaws. The term "golden beryl" is sometimes synonymous with heliodor. Both golden beryl and heliodor are used as gems.
Morganite, also known as "pink beryl", "rose beryl", "pink emerald", and "cesian (or caesian) beryl", is a rare light pink to rose-colored gem-quality variety of beryl. Orange/yellow varieties of morganite can also be found, and color banding is common.

Pink beryl was first discovered on an island on the coast of Madagascar in 1910. In December 1910, the New York Academy of Sciences named the pink variety of beryl "morganite" after financier J. P. Morgan.
Red beryl (also known as "red emerald" or "scarlet emerald") is a red variety of beryl. It was first described in 1904 for an occurrence at Maynard's Claim (Pismire Knolls), Thomas Range, Juab County, Utah.
Red beryl is very rare and has only been reported from a handful of locations including: Wah Wah Mountains, Beaver County, Utah; Paramount Canyon and Round Mountain, Sierra County, New Mexico and Juab County, Utah. The greatest concentration of gem-grade red beryl comes from the Violet Claim in the Wah Wah Mountains of mid-western Utah, discovered in 1958. While gem beryls are ordinarily found in pegmatites and certain metamorphic stones, red beryl occurs in topaz-bearing rhyolites. It is formed by crystallizing under low pressure and high temperature from a pneumatolitic phase along fractures or within near-surface miarolitic cavities of the rhyolite.



Wednesday, 27 November 2013

Natural Fancy Champagne Diamonds

Thirty years ago, Champagne diamonds were seldom seen on the market, until the Argyle Mine in Western Australia began raising international awareness of their alluring beauty. Since then, Champagne diamonds have become the ultimate fashion accessory for A-List celebrities and style trendsetters worldwide.
Argyle Diamonds has devised the C1 to C7 colour scale to grade champagne diamonds.

Gemologists use three terms to describe color in natural colored diamonds:

Hue: the dominant color of the natural diamond. Sometimes, modifying colors or tints can affect the hue of a diamond.

Tone: the amount of lightness or darkness in the natural colored diamond. The range of tone extends from light to dark.

Saturation: the strength or intensity of color in the natural diamond. The saturation of light in diamonds can vary from pastel to vivid and intense. The darker and more intense the color, the rarer and more expensive the diamond.

A famous Champagne colored diamond is the Golden Jubilee. The diamond weighs 545.67-carats and is known as the largest faceted diamond in the world. The rough was 755-carats and was discovered in the Premier mine in South Africa in 1985. As a gift for the 50th anniversary of his coronation, the Golden Jubilee was presented to the King of Thailand in 1997.



Sunday, 24 November 2013

Faberge attic find brings $ 5.2m

The executor of a Rhinebeck, New York estate made a huge discovery in the attic of George and Betty Davis, finding a rare Fabergé figure that recently sold at auction for $5.2 million. An unassuming wooden box held a hardstone portrait figure of Nikolai Nikolaievich Pustynnikov, who was a loyal personal Cossack bodyguard to Empress Alexandra Feodorovna.


“Little sapphires in the eyes, little gold trim and gold braid and all these elaborately inlayed and enameled double-headed imperial eagles." Tsar Nicholas II commissioned the famed artisans to produce the figure for his wife, Empress Alexandra in 1912, only a few years before the revolution that led to the fall of the Romanov family. Just 50 figures were known to have been carved by Fabergé.

The rarity of such figures is close to that of the Imperial Easter Eggs though production of portrait figures of known historical persons is even more rare for the House of Fabergé. The bill of sale shows that the figure was acquired by Armand Hammer. Then in December 1934 the antique was sold at the Hammer Galleries in Manhattan to Mr. George Davis for $2250.

It remained in the Davis family until the recent Stair Galleries auction in Hudson, New York.

The pre-sale auction estimate was $500,000-$800,000 for the authenticated figure that was found 6 months ago. Bidding began at $500,000 and when the gavel fell, famed London-based jeweler, Wartski, won the auction with a phone bid of $5.2 million.



http://news.yahoo.com/video/figurine-found-attic-sells-5-223209547.html?vp=1

Tuesday, 19 November 2013

Diamond Mining of Angola

Angola, the world's fourth-largest diamond producing country by value and sixth by volume, could regain record production levels enjoyed before 2002 thanks to its new mining law and higher quality diamonds, says a new study.
Angola’s diamond industry, which began a century ago under Portuguese colonial rule, is successfully emerging from a long period of difficulty as a result of a civil war that ended in 2002.

The country’s production volume has remained relatively stable at 8 million carats per year since 2006.
Over the last five years, while production remained fairly steady at the Catoca mine – the world’s fourth largest diamond mine in which Russia’s Alrosa is a joint venture partner – the impact of the financial crisis slowed production across the country and prompted international mining companies to abandon their operations. That trend is now starting to reverse.

Angola is also known for its significant gold and oil reserves.



http://www.mining.com/angolas-diamond-industry-to-regain-record-production-levels-report-29501/

Sunday, 17 November 2013

The Madre de Dios region of the Peruvian Amazon


A combination of field surveys, airborne mapping, and high-resolution satellite imaging have determined that small clandestine operations now make up more than half of all gold mining activities in the Western Amazonian forests of Peru.
The Carnegie Institution for Science and Peru’s Ministerio del Ambiente in Lima assessed road- and river-based gold mining in the Madre de Dios region of the Peruvian Amazon from 1999 to 2012. During this period, the geographic extent of gold mining increased 400%. In the year 2008, the average annual rate of forest loss as a result of gold mining tripled.

Madre de Dios now supplies more than 70% of Peru’s gold production; however, mining activities remain mostly unpermitted by the government.

The authors discovered hundreds of new small mines in the foothills in the headwater region of the Colorado, Inambari, and Malinowski Rivers.
Their discovery was confirmed by air in July 2011 and again in September 2013.

“Critically, as of 2012, small mining operations constituted 51% of the total mining activity throughout the region,” the authors observed. “Our results reveal far more forest damage than has been reported in the past, both in terms of the current area affected and the rate of clearing over time,”
While the total land loss in Madre de Dios appears small compared to other tropical regions undergoing deforestation, the study emphasized that “Madre de Dios is world-renowned for its unusually high biological diversity."


http://www.mineweb.com/mineweb/content/en//mineweb-sustainable-mining?oid=210498&sn=Detail