botryolite
noun[Gr. supra, and stone.]
Literally, grape-stone. This mineral occurs in mammilliary or botryoidal concretions, in a bed of magnetic iron in gneiss, near Arendal in Norway. Its colors are pearl-gray, grayish or reddish white, and pale rose-red, and form concentric stripes. Botryolite is a variety of siliceous borate of lime. It is found near the Passaic falls in New Jersey.