Feldspar Crystals in Basalt Chunk

Weight 115g | 6x5x1cm approx.

Feldspar is the most abundant mineral group in the Earth’s crust.

There are more feldspars (60%) than all the other minerals combined in the outer (13-17) km of the crust1. Feldspars occur in most igneous and metamorphic rocks.

They are less common in sedimentary rocks as they tend to break down to clay minerals in the weathering environment.

Feldspars are broadly divided into two groups: alkali feldspars and plagioclase feldspars. Common alkali feldspars are orthoclase, microcline, adularia, and sanidine. Plagioclase feldspars are albite, oligoclase, andesine, labradorite, bytownite, and anorthite.

This piece has a lacquered finish on one side.