Greensand

• POS: Noun
• HYPHEN: green=sand

CIDE DICTIONARY

Greensand, n. 

 A variety of sandstone, usually imperfectly consolidated, consisting largely of glauconite, a silicate of iron and potash of a green color, mixed with sand and a trace of phosphate of lime.  [1913 Webster]
" Greensand is often called marl, because it is a useful fertilizer. The greensand beds of the American Cretaceous belong mostly to the Upper Cretaceous."  [1913 Webster]

OXFORD DICTIONARY

Greensand, n.
1 a greenish kind of sandstone, often imperfectly cemented.
2 a stratum largely formed of this sandstone.