greensand

noun

1. (countable, uncountable)A greenish sandstone containing glauconite.

   “The numerous beds of coarse Oolites, which in England in general occur below the lyas and greensand, are entirely wanting in Ireland: But this is the case also in the neighbourhood of Lime-Regis in Dorsetshire, which place affords an exact counterpart of the Irish series here described.”

   “The Sassafras soils occur on the Atlantic coastal plain from the mouth of Chesapeake Bay to Long Island. They are developed from coastal-plain materials consisting of sand and clay, free from lime carbonates or greensand.”

   “Glauconite occurs as granules which may be mixed in all proportions with ordinary sand. Some greensands contain over fifty percent glauconite. The glauconite may be concentrated in certain laminations or scattered throughout the sand. If abundant enough, it imparts a speckled appearance to the rock.”

   “A useful product called greensand (glauconite) is mined from petrified seaweed deposits. In addition to potassium, greensand contains a whole range of trace elements, also called micronutrients, which are minor minerals like iron, sulfur, zinc, copper, and boron. We call them minor because they are only needed in small amounts by plants, but they are nonetheless vital to plant health and vigor.”