umber

umber

1. any of various natural brown earths containing ferric oxide together with lime and oxides of aluminium, manganese, and silicon

2. any of the dark brown to greenish-brown colours produced by this pigment

3. Obsolete

a. any dark, dusky, or indefinite colour

Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

umber

[′əm·bər]

(materials)

A naturally occurring brown siliceous earth, deriving its color from iron oxides and manganese oxide; used as a paint pigment.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

umber

A naturally occurring brown siliceous earth, containing hydrated iron oxide with small amounts of manganese oxide; used as a pigment in paint; turns red to reddish-brown when calcined, and then is called burnt umber.

McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.