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

random

Pest Alert: Asian Giant Hornet (www2.gov.bc.ca) Three Asian Hornets (Vespa mandarinia) were found in the Nanaimo area on Vancouver Island in mid-August [of 2019]. The identification has been confirmed by Canadian and international experts. This is the first time this insect has been found in British Columbia.

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).