Alkali feldspar granite Alkali feldspar granite Alkali feldspar granite, some varieties of which are called 'red granite', is a felsic igneous rock and a type of granite rich in the mineral potassium feldspar (K-spar). It is a dense rock with a phaneritic texture. The abundance of K-spar gives the rock a predominant pink to reddish hue; peppered with minor amounts of black minerals. As shown in the QAPF diagram, alkali feldspar granite contains between 20% - 60% quartz. Less quartz content would lead to "quartz alkali feldspar syenite". More than 90% of the total feldspar content is in the form of alkali feldspar.
Fall River granite steeples was constructed of Fall River granite. Unfortunately this building was destroyed by fire on May 11, 1982. The Chateau-sur-Mer mansion in Newport, Rhode Island is perhaps the best example of Fall River granite being used for private home construction. Fall River granite Fall River granite is a Precambrian bedrock underlying the City of Fall River, Massachusetts and surrounding areas along the eastern shores of Narragansett Bay. It was formed 600 million years ago, as part of the Avalon terrane. During the 19th century, the City of Fall River, Massachusetts became famous for the granite rock on which much of