Crossword clues for glauconite
The Collaborative International Dictionary
Glauconite \Glau"co*nite\, n. [Cf. F. glauconite, glauconie, fr. L. glaucus. See Glaucous.] (Min.) The green mineral characteristic of the greensand of the chalk and other formations. It is a hydrous silicate of iron and potash. See Greensand.
Wiktionary
n. (context mineral English) A greenish form of mica found in greensand.
WordNet
n. a green mineral consisting of hydrated silicate of potassium or iron or magnesium or aluminum; found in greensand
Wikipedia
Glauconite is an iron potassium phyllosilicate ( mica group) mineral of characteristic green color with very low weathering resistance and very friable.
It crystallizes with a monoclinic geometry. Its name is derived from the Greek glaucos (γλαυκος) meaning 'blue', referring to the common blue-green color of the mineral; its sheen (mica glimmer) and blue-green color presumably relating to the sea's surface. Its color ranges from olive green, black green to bluish green, and yellowish on exposed surfaces due to oxidation. In the Mohs scale it has hardness of 2. The relative specific gravity range is 2.4 - 2.95. It is normally found in dark green rounded brittle pellets, and with the dimension of a sand grain size. It can be confused with chlorite (also of green color) or with a clay mineral.Glauconite has the chemical formula – (K,Na,Ca)1.2-2.0(Fe+3,Al,Fe+2,Mg)4(Si7-7.6Al1-0.4)020(OH)2.nH2O
Glauconite particles are one of the main components of greensand and glauconitic sandstone, and glauconite has been called a marl in an old and broad sense of that word. Thus references to "greensand marl" sometimes refer specifically to glauconite. The Glauconitic Marl formation is named after it, and there is a Glauconitic Sandstone formation in the Mannville Group of Western Canada.
Usage examples of "glauconite".
The sequence we would expect to see, therefore, would be nearshore sands with glauconite, then beach or barrier island sand, then a lagoon with vegetated tidal flats, and finally the mainland.
The sand layers had a greenish tint produced by a mineral called glauconite, almost always the sign of a marine or coastal environment.