Definition
Origin
Discoverer
Etymology
Class
Sub-Class
Group
Other Categories
Nepheline Syenite is a holocrystalline plutonic rock resembling syenite but containing nepheline and lacking quartz
From origin of a Palaeozoic nepheline syenite from northern Shanxi Province, China
Durable Rock, Medium Hardness Rock
Fine Grained Rock, Opaque Rock
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use
Fine Grained Rock, Opaque Rock