chalcedony

agate

Agate is a variety of chalcedony characterized by either transparency or color patterns, such as multi-colored curved or angular banding. Opaque varieties are sometimes referred to as jasper.

history

In the Bronze Age chalcedony was in use in the Mediterranean region; for example, on Minoan Crete at the Palace of Knossos, chalcedony seals have been recovered dating to circa 1800 BC.

path on GitHub

https://github.com/davepinch/pinchy.cc/blob/master/content/topics/geology/minerals/chalcedony/chalcedony.md

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American Dream (Wikipedia) The American Dream is the national ethos of the United States, that every person has the freedom and opportunity to succeed and attain a better life. The phrase has had different meanings over time. Originally, the emphasis was on democracy, liberty and equality, rather than on material wealth and upward mobility.

tags

variety

Wikidata

https://www.wikidata.org/wiki/Q170448

Wikipedia

Chalcedony (Wikipedia) Chalcedony (/kælˈsɛdəni/ kal-SED-ə-nee, or /ˈkælsəˌdoʊni/ KAL-sə-doh-nee) is a cryptocrystalline form of silica, composed of very fine intergrowths of quartz and moganite. These are both silica minerals, but they differ in that quartz has a trigonal crystal structure, while moganite is monoclinic. Chalcedony’s standard chemical structure (based on the chemical structure of quartz) is SiO2 (silicon dioxide).