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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 ...
Stones that show a dramatic color change and strong colors (e.g., red-to-green) are rare and sought-after, [8] but stones that show less distinct colors (e.g. yellowish green changing to brownish yellow) may also be considered "alexandrite" by gem labs such as the Gemological Institute of America. [13] [14]
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 ]
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.
A star sapphire is a type of sapphire that exhibits a star-like phenomenon known as asterism; red stones are known as "star rubies". Star sapphires contain intersecting needle-like inclusions following the underlying crystal structure that causes the appearance of a six-rayed "star"-shaped pattern when viewed with a single overhead light source.
Retiring abroad can offer more affordable health care and better quality of life, so check out this list with the top locations in the world to retire. List reveals the top 10 best places in the ...
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.