agate

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agate

Geology
A microcrystalline silicate, which is characterised by fine grain and bright colours.
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Lake Superior agates developed a billion years ago when a hot spot of molten lava formed under what is today Lake Superior.
Much later, Lake Superior agates were made into marbles.
This property adjoins the acclaimed historic fire agate gemstone mines, 'The One Track Mine' and 'The Deer Creek Fire Agate Mine', otherwise known as The Penny Pit.
Thomas creates lamp finials out of slivers of malachite, howlite and agate, as well as unusual specimens like inky iridescent labradorite, creamy blue-tinged chrysophase and petrified wood.
Native Americans considered chalcedony -- the family of minerals that includes jasper, onyx and agate -- capable of imparting strength and courage.
Geologically speaking, agates are nodular masses comprising one or more varieties of quartz, particularly chalcedony.
Part of the fascination of agates is the wide range of forms and colours they can exhibit, no two agates looking exactly alike.
Mexican agates show most of the features known in agates of volcanic origin worldwide.
Museum-quality agates have never been plentiful, even in the 1940s, when large-scale surface collecting began.
Agate, a type of quartz whose iridescent patterns sparkle with color, has long been valued as a semiprecious stone.
Davis, a geological chemist at the University of Chicago, show that concentric shells of fine and coarse crystals alternate to create agate's light-diffracting "iris" bands.
The main theme of the Show this year was "Agate Dreams," and Keilmann gathered together a museum of worldwide agate specimens that far exceeded, in scope and quality, any such assemblage ever shown anywhere.