Monday, 19 September 2016

Spinel of Mahenge, Tanzania

Spinel is magnesium aluminum oxide with the formula MgAl2O4. The name "spinel" comes from either the Latin word "spina" meaning "thorn", due to its characteristic octahedral crystals having pointed ends, or the Greek word "spintharis" meaning "spark".

Although spinel occurs in a range of different colors, the pink to red variety is the one that is commercially important. Spinel is single refractive and doesn't have pleochroism. It belongs to the cubic crystal system with hardness of 8.0 on the Mohs scale.
Spinel offers a range of hues from orange to intense red, vibrant pink, and all shades between purple, blue and violet through to bluish green.
Historically, the most famous red spinels came from the Balas region of Afghanistan and were known as Balas rubies. Some of the most famous rubies in the world, such as the Black Prince's Ruby, part of the British Crown Jewels, are actually spinels. More recently, Sri Lanka and Burma has been the main source for fine spinel.

The highest quality transparent blood-red "ruby spinel" and hot-pink spinel has come from mines in Mogok, Upper Burma.
In 2007 several huge spinel crystals were discovered at Ipanko, near the town of Mahenge, in Tanzania. Miners unearthed spinel crystals weighing from six to 54 kg.
The crystal was highly included, but large chunks of top quality stone were able to be cobbed off.
The spinel crystal displayed the vibrant pink color that is now famous from Mahenge Spinel. Thousands of carats of gem quality gems were cut in Thailand and distributed into the world market.

From this point on Mahenge Spinel was thrust into the world spotlight.
Spinel is highly sought after by gem connoisseurs, and well-formed spinel crystals are in high demand among collectors. Red spinel range from orange-red to purplish red, with pure red considered the finest of all.

A top-quality 5 carat red spinel might sell for around a tenth the price of an equivalent-quality ruby, and pink spinel often sells for less than pink sapphire.
Tanzania is now the world's second largest supplier of spinel in the pink-to-red range. Spinel also has been found in Ipanko and Matombo.

Since the Mahenge spinel is still a recent discovery, there is still top quality material available for collectors.

Weathered marble outcrops tower over the spinel diggings of Ipanko, near Mahenge.
The Imperial Crown of Russia, also known as the Great Imperial Crown, was made for the Empress Catherine II the Great's Coronation in 1762. The crown is set with around 5000 diamonds from India arranged in a pattern of laurel wreaths and oak branches and a number of fine large white pearls.

It is topped with one of the seven historic stones of the Russia's Diamond Collection - a large precious red spinel weighing 398.72 carats. The Imperial Crown of Russia is currently on display in the Moscow Kremlin Armoury State Diamond Fund.
The Imperial State Crown is the most magnificent of all the Crown Regalia. It was made in 1838 for the Coronation of Queen Victoria, and then altered for the Coronation of George VI in 1937 and Elizabeth II in 1953. It is usually worn at the end of the coronation ceremony, when the newly-crowned monarch departs from Westminster Abbey. Although the crown is modern in design, it is set with very old gems.

The Black Prince’s Ruby (spinel), roughly 170 carats, is set into the central panel of the crown.

Tuesday, 13 September 2016

Ancient gold coins, gold plate, found in India

A total of 117 gold coins, a small gold plate and two silver anklets were found in an agricultural field in a village in Kadambur block in Sathyamangalam taluk in 2012.

The coins reportedly belong to the period of the Vijayanagara dynasty. A group of workers stumbled on a pot which contained the treasure when they were harvesting tapioca tuber in a field in Karaliyam, a village located inside the Kadambur forests.

The Vijayanagara empire was an Indian empire that existed from 1336 through 1660. It was founded by Harihara (Hakka) and his brother Bukka Raya.

The empire is named after its capital city Vijayanagara, now Hampi in modern Karnataka, India.

Monday, 12 September 2016

Gold-hilted sword found beneath a Scottish soccer field may be 4,000 years old

Excavations have revealed a trove of ancient artifacts, which could date back to the Bronze Age.

Diggers moved into the site in Carnoustie after relics were found while laying foundations for a new sports field.

Famed for its golfing heritage the small Tayside town could now hold the key to how Scots lived as early as 2000BC.

Facial Reconstruction Of Ava: 3,700-Year-Old Bronze Age Woman
Evidence for Bronze Age dwellers in Scotland is widespread. A recreation of a skeleton earlier this year indicated the people who inhabited the Scottish Highlands at this time looked similar to today's citizens.

Known as 'Ava', the Bronze Age woman died more than 3,700 years ago, but was brought back to life in a two-dimensional image in July.

Thursday, 8 September 2016

Bronze Age burial on Cyprus reveals ancient artifacts

A tomb discovered at the Late Bronze Age site of Dromolaxia-Vizakia, (Hala Sultan Tekke) in Cyprus has revealed one of the richest bronze age burials ever discovered on Cyprus, dating back to 1500 BC.

The burial belonged to a rich family and had hidden treasures of over 100 ceramic vessels and precious gold ornaments and gem stones that were from several adjacent cultures, reaffirming Cyprus's place in history as an intricate player in long-distance trade.
Gemstones and five cylinder seals that came from the region as well as from Syria and Mesopotamia, along with gold earrings and gold Egyptian scarabs were found. The ruins date back to 1500 to 1400 BC.

Wednesday, 7 September 2016

Strange and Unusual Places

Tufa pinnacles at Mono Lake in Sierra Nevada - Mono Lake is a closed hydrological basin - water flows into it but it doesn't flow out. The only way for water to leave is through evaporation. Four vertical feet of water can evaporate during the course of a year.

Lake Baikal in Siberia freezes over but the water is so clear that you can see an astounding 130 feet below you. Wind, temperature differences, frost and sun in the ice crust cause cracks and ice hummocks to form.

A lightning bolt crashed against the Grand Canyon illuminating the steep canyon walls. The bright blue bolt illuminated the South Rim of the canyon, considered one of the Seven Natural Wonders of the World.
The Door to Hell is a natural gas field in Derweze, Ahal Province, Turkmenistan. The Door to Hell is noted for its natural gas fire which has been burning continuously since it was lit by Soviet petroleum engineers in 1971.

The elephant rock formation in Valley of Fire State Park in Nevada - A strange natural sandstone rock formation resembling an elephant.
Don Juan Pond is a shallow hypersaline lake in the west end of Wright Valley, Antarctica. With a salinity level of over 40%, Don Juan Pond is the saltiest known body of water on Earth

The Great Blue Hole in Belize - A large submarine sinkhole which is over 984 feet across and 407 feet deep. The sinkhole was formed during several episodes of quaternary glaciation when sea levels were much lower.

The Dune of Pilat is the tallest sand dune in Europe. It is located in La Teste-de-Buch in France, 60 km from Bordeaux.

The Wave in Utah - Carved rock eroded into a wave-like formation made of jurassic-age Navajo sandstone that is approximately 190 million years old.

Aogashima is south of Tokyo in the Philippine Sea. The island is known for having a volcanic caldera within a larger caldera.

The sliding stones of Death Valley, California - The movement of the rocks continue to baffle experts, with some rocks sliding across a flat bed despite weighing up to 700 pounds each.

Urup is an uninhabited volcanic island near in the south of the Kuril Islands chain in the Sea of Okhotsk in the northwest Pacific Ocean

The Beauty Pool of Yellowstone National ParkThe hot spring allows luminous algae and bacteria to flourish creating a vivid array of colors

Fraser Island is considered to be the largest sand island in the world at 1840 km².

Danxia Landforms in Zhangye, Province of Gansu

Thor’s Well, Oregon

The Moeraki Boulders of New Zealand The gigantic boulders started forming on the ocean floor and can now be seen sitting on the coastline thanks to erosion.
The Eye of Africa official name the Richat Structure was spotted in central Mauritania by astronauts on early space missions. In the expanse of the Western Sahara Desert, the formation has a diameter of about 30 miles.

Seaside lava ledges on Kauaʻi of the main Hawaiian Islands.

The Fly Geyser, near Gerlach, Nevada