from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A hydrated ferrous silicate related to serpentine
from The Century Dictionary and Cyclopedia
- n. In petrography, metamorphosed rock composed largely of minute granules of green hydrous ferrous silicate.
Sorry, no etymologies found.
The original condition is indicated by the facts that deep below the surface, in zones protected from weathering solutions, siderite and greenalite are abundant, and that they show complete gradation to hematite in approaching the surface.
When originally deposited the iron was partly hematite (perhaps some magnetite) and largely in the form of iron carbonate (siderite) and iron silicate (greenalite), interbanded with chert.