granulite

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A metamorphic rock consisting of similarly sized, interlocking minerals, especially feldspar, quartz, and garnet, and lacking the layering and foliation characteristic of other metamorphic rocks.

from The Century Dictionary.

• noun A rock often having a parallel or foliated structure like that of gneiss, and consisting mainly of quartz and feldspar, together with red garnets, which are usually of very diminutive size.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Geol.) A whitish, granular rock, consisting of feldspar and quartz intimately mixed; -- sometimes called whitestone, and leptynite.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun geology A fine-grained metamorphic rock composed chiefly of feldspar, quartz, and garnets