Definition
Origin
Discoverer
Etymology
Class
Sub-Class
Group
Other Categories
Variolites are a group of dark green basic igneous rocks which exhibit pale colored spots, or spherules, especially on weathered surfaces, that give them a pockmarked appearance
From Latin varius, speckled, variegated
Hyaloclastite is an aggregate of fine, glassy debris formed by the sudden contact of hot, coherent magma and cold water or water-saturated sediment
Fine Grained Rock, Opaque Rock