Definition
Origin
Discoverer
Etymology
Class
Sub-Class
Group
Other Categories
Rhyodacite is an extrusive volcanic rock intermediate in composition between dacite and rhyolite
Rhyo lite + dacite : a rock intermediate between rhyolite and dacite that is the extrusive equivalent of granodiorite
Durable Rock, Medium Hardness Rock
Fine Grained Rock, Opaque Rock
Lamprophyre is uncommon igneous rocks primarily occurring as dikes, lopoliths, laccoliths, stocks and small intrusions
From Greek lampros bright and shining + porphureos purple
Durable Rock, Medium Hardness Rock
Coarse Grained Rock, Fine Grained Rock, Opaque Rock