Commodity Code

smokey quartz

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

definition Smoky quartz is a brown to black variety of quartz more like this
notation
01.03.25.04 more like this
SQtz more like this
source http://en.wikipedia.org/wiki/Smoky_quartz more like this
type
Resource
Concept
broader quartz gemstone
narrower smokey quartz
in scheme commodity code
is primary topic of smokey quartz