Search results
Results from the WOW.Com Content Network
The Alexandrite effect has also been observed in some other minerals, such as fluorite, sapphire, kyanite, monazite, spinel, garnet, tourmaline, and rare-earth oxalates. Not to be confused with the alexandrite effect, some minerals also exhibit pleochroism. The former is a response to different wavelengths of light in general, the latter an ...
However, discoveries and inventions are inextricably related, in that discoveries lead to inventions, and inventions facilitate discoveries; and since the same phenomenon of multiplicity occurs in relation to both discoveries and inventions, this article lists both multiple discoveries and multiple inventions.
Tetragonal, trigonal, and hexagonal minerals can only show two colors and are called dichroic. Orthorhombic , monoclinic , and triclinic crystals can show three and are trichroic. For example, hypersthene , which has two optical axes, can have a red, yellow, or blue appearance when oriented in three different ways in three-dimensional space. [ 5 ]
Devon Island, in the Canadian North, is the world's largest uninhabited island. Northeast Greenland National Park, which is the world's largest terrestrial protected area, has had a census population of 0 for many years since the only mine in the region closed. Nevertheless parts of this remote area can see seasonal use: 31 people and about 110 ...
The Seven Wonders of the Ancient World (from left to right, top to bottom): Great Pyramid of Giza, Hanging Gardens of Babylon, Temple of Artemis at Ephesus, Statue of Zeus at Olympia, Mausoleum at Halicarnassus (also known as the Mausoleum of Mausolus), Colossus of Rhodes, and the Lighthouse of Alexandria as depicted by 16th-century Dutch artist Maarten van Heemskerck.
16th-century imagined depictions of the Seven Wonders of the Ancient World. From left to right, top to bottom: Great Pyramid of Giza, Hanging Gardens of Babylon, Temple of Artemis, Statue of Zeus at Olympia, Mausoleum at Halicarnassus, Colossus of Rhodes, and the Lighthouse of Alexandria Timeline, and map of the Seven Wonders.
Synthetic alexandrite is an artificially grown crystalline variety of chrysoberyl, composed of beryllium aluminum oxide (BeAl 2 O 4). The name is also often used erroneously to describe synthetically-grown corundum that simulates the appearance of alexandrite , but with a different mineral composition.
Main chrysoberyl producing countries. The mineral or gemstone chrysoberyl is an aluminate of beryllium with the formula Be Al 2 O 4. [5] [6] The name chrysoberyl is derived from the Greek words χρυσός chrysos and βήρυλλος beryllos, meaning "a gold-white spar".