Product Description

Introduction

Feldspar is the most common rock-forming mineral (about *0% of the earth’s crust) (Kauffman and Van Dyk, ***4). The mineral name feldspar is derived from the German words feld + spar. The word "feld" is "field" in German and "spar" is a term for light colored minerals that break with a smooth surface. Feldspar minerals are usually white or very light in color, have a hardness of 6 on the Mohs’ Scale of Hardness and perfect to good cleavage (plane of breakage) in two directions.

Feldspar is a common name that applies to a group of minerals with a general chemical formula of x Al(Al,Si)3O8, where x can be sodium (Na) and/or calcium (Ca) and/or potassium (K). (Specific compositional varieties (i.e. albite, microcline…) are discussed under Mineral Descriptions).

Feldspar occurs in igneous, metamorphic and sedimentary rocks and thus can be found throughout North Carolina. It is more commonly found in igneous and metamorphic rocks of the Blue Ridge and Piedmont provinces. Feldspar weathers to kaolin which is the main clay mineral used in ceramics and fine pottery.