Wednesday, 30 October 2013

Sapphire Mining in Ilakaka-Sakaraha, Madagascar


A parcel of sapphire and chrysoberyl from the Ilakaka-Sakaraha deposit in southern Madagascar.
The Ilakaka-Sakaraha deposit in Madagascar is probably the world’s largest sapphire producer over the past 13 years.

The first discovery was in 1998, near Ilakaka Be. Locals quickly established a thriving market with Thai and Malagasy merchants. Within months, miners from around the island settled near the bridge on the Ilakaka River, and a boomtown was born. Ilakaka is a much quieter place today. Tourists regularly stop there, while Sri Lankan, Thai, and Malagasy gem traders still conduct business.

(click to enlarge)
The deposit extends about 120 km east from Anena to Anakondro, and nearly 100 km north from Anena to Antaralava.
In the Taheza basin the sapphire-rich gravels are usually about 30 meters deep, but some artisanal miners use a 50-meter vertical shaft to reach the gravels, which are mined by digging narrow horizontal tunnels. For the digger to breathe, air has to be sent underground using large plastic bags and tubes. The gravels are extracted and taken to the river for washing.
Overall, mining and trading around Ilakaka is down from previous years. But with 10,000–20,000 miners and several hundred buyers, Ilakaka-Sakaraha probably still surpasses Ratnapura and Elahera in Sri Lanka as the world’s main source for blue and pink sapphires.

From April to July 2012, many of the buyers and miners left Ilakaka to work in the jungle near Didy and Ambatondrazaka, where fine rubies and sapphires were discovered in March 2012.




Tuesday, 29 October 2013

Alrosa uncovers 235 carat diamond

A diamond weighing 235.16 carats has been found in Russia’s Siberian republic of Yakutia, Russia’s biggest diamond miner, Alrosa, said. A company spokesman told the Prime business news agency that the uncut diamond was of gem quality. The diamond is octahedral in shape, transparent, slightly yellowish in color, and bears only slight graphite-sulfide inclusions in peripheral areas.

Alrosa accounts for 97 percent of all diamonds mined in Russia and a quarter of global output. The company’s sales of rough and polished diamonds stood at $4.61 billion last year.
http://en.ria.ru/russia/20131009/184034647/15M-2M-Diamond-Found-in-Siberia.html

Monday, 28 October 2013

Beyond El Dorado

For centuries Europeans were dazzled by the legend of a lost city of gold in South America. The truth behind this myth is even more fascinating. El Dorado – literally “the golden one” – actually refers to the ritual that took place at Lake Guatavita, near modern Bogotá.
The British Museum has created an exhibit featuring 200 artefacts from Bogota’s Museum of Gold. This exhibition looks at the reality behind the stories that excited the European imagination from the 16th century onwards, telling of a lake into which a ruler entirely covered in gold — the El Dorado or Golden One — made offerings of gold and emeralds.

http://www.telegraph.co.uk/culture/art/art-reviews/10379433/Beyond-El-Dorado-Power-and-Gold-in-Ancient-Colombia-British-Museum-review.html
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Laguna de Guatavita is located in the municipality of Sesquilé, in the Cundinamarca Department of Colombia, 35 miles north-east of Bogotá.

Laguna de Guatavita was one of the sacred lakes of the Muisca, and a ritual conducted there is thought to be the basis for the legend of El Dorado. The lake is where the Muisca celebrated a ritual in which the Zipa (named "El Dorado" by the Conquistadores) was covered in gold dust, then venturing out into the water on a ceremonial raft made of rushes, he dived into the waters washing off the gold.
Afterward, trinkets, jewelry, and other precious offerings were thrown into the waters by worshipers.
Conquistadores Lázaro Fonte and Hernán Perez de Quesada attempted to drain the lake in 1545 using a "bucket chain" of labourers. After 3 months, the water level had been reduced by 3 metres, and only a small amount of gold was recovered.

In 1580 Antonio de Sepúlveda had a notch cut deep into the rim of the lake, which managed to reduce the water level by 20 metres, before collapsing and killing many of the labourers. Various golden ornaments, jewellery and armour were found. Sepúlveda died a poor man, and is buried at the church in the small town of Guatavita.

In 1898 the lake was successfully drained by means of a tunnel that emerged in the centre. The water was eventually drained to a depth of about 4 feet of mud and slime. This made it impossible to explore, and when the mud had dried in the sun, it set like concrete. A haul of only £500 was found, and subsequently auctioned at Sothebys of London.

The Colombian government has disallowed any more draining attempts.
Pre-Columbian Ecuador included indigenous cultures that developed for thousands of years before the ascent of the Incan Empire.
There are major archaeological sites in the coastal provinces of Manabí and Esmeraldas and in the middle Andean highland provinces of Tungurahua and Chimborazo. The archaeological evidence has established that Ecuador was inhabited for at least 4,500 years before the rise of the Inca.
The invasion of the Inca in the 15th century was bloody. Once over, the Incas developed an extensive administration and began the colonization of the region.




Sunday, 27 October 2013

Soviets recover half tonne meteorite

Divers have brought to shore a 570-kilogram (1,256 pounds) chunk of a meteorite which had blazed over the Russian town of Chelyabinsk in February. Its impact was the largest on record in decades.

The meteorite shower on February 7 over Chelybinsk - just north of Kazahkstan - left at least 1,200 injured and reportedly damaged a number of buildings. Media reports estimated the shock wave from the meteor was as strong as roughly 20 nuclear bombs.
http://ca.news.yahoo.com/video/half-tonne-meteorite-recovered-182900971.html

Friday, 25 October 2013

Victoria's Secret unveils $ 10m Bra

(IDEX Online News) – The holiday season wouldn’t be the holiday season without Victoria’s Secret’s annual fantasy bra. This year, the bejeweled undergarment has been designed by Mouawad and will be worn by Victoria’s Secret Angel Candice Swanepoel who will model the Fantasy Bra in the 2013 Victoria’s Secret Dreams & Fantasies Catalogue as well as at The Victoria’s Secret Fashion Show, scheduled to air on December 10.

The Royal Fantasy bra and matching belt are adorned with more than 4,200 precious gems, including rubies, diamonds, and yellow sapphires. The 18-karat gold bra also features a 52-carat, pear-shaped ruby at its eye-catching center.

Mouawad has some experience in the brassiere department. The jeweler created a 10-karat white gold bra set with 2,900 diamonds in 2004. The Heavenly '70s Fantasy bra, which featured 112 carats of gems – including a flawless 70-carat pear-shaped diamond in the center – was also valued at $10 million.



Thursday, 24 October 2013

Stones of the Bible II

Chrysoprase is a translucent, bright apple or grassy green variety of chalcedony. The green color comes from nickle. It is the most valuable variety of chalcedony. Chrysoprase has been discovered in archaeological digs in ancient Egypt. A necklace which included chrysoprase beads was found on a mummy dating back to 1500 BC.

The most famous deposits of ancient chrysoprase came from Silesia.
Coral is a limestone formation of calcium carbonate produced by the skeletons of millions of tiny marine animals (polyps). Since it is of animal origin it is not technically a mineral. Gem quality coral or precious coral is only found in a few places in the world, one being the warm waters of the Mediterranean Sea which produces some of the very finest. It grows in bush-like clumps of branches about a foot high and must be harvested while still living to preserve the color. If the polyps die before a branch reaches the surface, the coral turns dark and loses its value. Coral has been harvested from the earliest times and was highly prized by many civilizations throughout history.
Diamonds are pure, elemental carbon. Hardest of all gemstones, diamonds have the highest melting point of any substance (3,820 degrees Kelvin), is an excellent heat conductor, and has very low reactivity to chemicals. The English word “diamond” comes from the Greek word adamas meaning “the invincible.” Diamonds were not identified until the first century, and then they were valued as a tool for carving other stones.

Pliny the Elder describes diamond crystals from India around 77 AD.
Emeralds are a variety of beryl. Emeralds were well known to biblical lands. One of the earliest known source of emerald were mines located near the Red Sea in Egypt.

There is evidence that these mines were in operation as early as 1600 B.C. Later they became known as Cleopatra’s Mines, as she was quite fond of emeralds and was reported to wear them to enhance her beauty. Emeralds engraved with her likeness were given as gifts to her guests.
Garnet is a brittle, hard, glassy, mineral silicate. Though the word “garnet” is not found in any of the translations of the Bible, garnets were a common stone in biblical times.

The garnet has been found as early as the Bronze Age, dating back to 3100 B.C.in Egyptian jewelry. Garnets have been closely associated with blood due to their colour and have very often been mistaken for rubies throughout history. (Rubies came into use around 400 B.C. with the Roman Empire)
Jasper is an opaque variety of chalcedony (quartz). It is most commonly red due to the presence of iron, but can also be found in yellow, brown and green. ”Jasper” comes from the Greek word iaspis which is a derivation of “to polish”.

One of characteristics of jasper is that it is able to take a high polish. It was used in ancient times as mantles, pillars, vases, and other interior decorations. Pliny the Elder lived and wrote around the same time that the book of Revelation was written, and describes iaspis as “being green and often transparent” which is of interest since today we consider jasper to be opaque.
Lapis Lazuli is an ultramarine-blue stone consisting largely of lazurite and speckled with yellow pyrite. Lapis was one of the most sought after and prized stones in the ancient world. It was used for jewelry, ornamentation, seals, and amulets. Egyptian blue paint was made from finely ground lapis. The stone has been found in many archaeological digs of ancient civilizations, including King Tut’s tomb.

Mines in Afghanistan have been producing gem lapis lazuli for nearly 5000 years and are still the worlds largest producer of the material. It is commonly agreed that lapis lazuli is actually the stone meant for the term “sapphire” in the bible. Sapphires were not known before the Roman empire and were initially thought to be jacinth.