Feldspar & Graphic Feldspar
Feldspar is found in igneous, metamorphic, and sedimentary rocks in all over the world. It is a group of rock-forming silicate minerals. Feldspar minerals make up over 50% of Earth's crust.
Graphic Felspar, also known as Zebradorite, is an intergrowth of quartz and feldspar which may appear as runic or cuneiform writing (hence the term), as darker and glassier quartz 'characters' or 'letters' in a groundmass of white feldspar (usually microcline). This is found almost exclusively in granitic pegmatites, and is believed to result from simultaneous growth of the feldspar and quartz under conditions which favored the planar growth of feldspar and the rods of quartz. [mindat.org]