A class of dense, dark-color silicaceous minerals that are high in iron, magnesium, calcium, and sodium. The high iron content of mafic clays are responsible for the surface crystalline formations produced in oil spot ceramic glazes. Examples of mafic rocks are basalt and gabbro. They may include olivine, pyroxene, amphibole, biotite, augite, and calcium-rich feldspars.
Synonyms and Related Terms
mafic clay; minerais máficos (Port.)
Sources Checked for Data in Record
- Submitted information Comment: José Delgado Rodrigues, LNEC, 2009.
- External source or communication Comment: Submitted information: Fred Gamble, October 2007.
- Wikipedia, the free encyclopedia, at http://www.wikipedia.com Comment: 'Mafic' (accessed October 5, 2007)
- Robert Fournier, Illustrated Dictionary of Practical Pottery, Chilton Book Company, Radnor, PA, 1992
- Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997
- The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998