from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A greenish mineral of the mica group, a hydrous silicate of potassium, iron, aluminum, or magnesium, (K,Na)(Al,Fe,Mg)2(Al,Si)4O10(OH)2, found in greensand and used as a fertilizer and water softener.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A greenish form of mica found in greensand
from the GNU version of the Collaborative International Dictionary of English
- n. The green mineral characteristic of the greensand of the chalk and other formations. It is a hydrous silicate of iron and potash. See greensand.
from The Century Dictionary and Cyclopedia
- n. A mineral which is essentially a hydrous silicate of iron and potassium. It is the “green earth” of the cavities of eruptive rocks, or the substance which gives the color to the grains of greensand and chalk.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a green mineral consisting of hydrated silicate of potassium or iron or magnesium or aluminum; found in greensand
Keller et al. (2004a,b) demonstrated that the impact breccia and the K-T boundary are separated by a 50 cm interval of sediments that contain (1) five thin glauconite clay layers, each of which represents deposition over tens of thousands of years, thus incompatible with tsunami or backwash deposition?
An opaque calcite of a grass-green colour, occurring as large cleavage masses in central India and known as hislopite, owes its colour to enclosed "green-earth" (glauconite and celadonite).
Iron likewise combines with a considerable variety of substances other than oxygen; and some of these compounds, as for instance iron carbonate (siderite), iron silicate (chamosite, glauconite, etc.), and iron sulphide (pyrite), are locally mined as iron ores.
Various potassium silicates -- leucite, feldspar, sericite, and glauconite -- and the potassium sulphate, alunite, have received attention and certain of them have been utilized to a small extent, but none of them are normally able to compete on the market.
The magnesia and potash are, also, largely restored from the ocean; the former in dolomites and magnesian limestones; the latter in glauconite sands.
A series of worm-holes traced erratic hieroglyphics across a scaling corner; all the varied texts were illuminated by quartzose particles glittering in the sun, and here and there fine green grains of glauconite.
Greensand is a sand or sediment that consists of dark greenish grains of glauconite that is usually mixed with clay or sand.