Igneous

MFA Acc. #: 1999.214

Description

Rocks that solidified from a hot, molten matrix such as magma or lava. When the magma cools slowly, individual components can crystalline and form coarse-grain rocks, such as granite, diorite, basalt, and syenite. When the magma or lava cools quickly, fine-grain minerals and glass-like rocks, such as rhyolite and obsidian, are formed.

Synonyms and Related Terms

igneo (Esp., Port.); ignée (Fr.); Magmatisch (Deut.)

Authority

• G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971

• Anne Grimmer, Glossary of Building Stone Terms, A Glossary of Historic Masonry Deterioration Problems and Preservation Treatments, National Park Service, Washington DC, 1984

• Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976

• 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