Commodity Code

obsidian

http://resource.geosciml.org/classifier/cgi/commodity-code/obsidian

definition Obsidian is the result of volcanic lava coming in contact with water. Often the lava pours into a lake or ocean and is cooled quickly. This process produces a glassy texture in the resulting rock. Iron and magnesium give the obsidian a dark green to black color. Obsidian has been used by ancient people as a cutting tool, for weapons, and for ceremonial purposes and is sometimes found by archaeologists in excavations. more like this
notation
01.03.21 more like this
Obs more like this
source http://www.galleries.com/Obsidian more like this
type
Resource
Concept
broader gemstones
narrower obsidian
in scheme commodity code
is primary topic of obsidian