👉 A walkerite is a type of mineral that is primarily found in the upper crust of metamorphic rocks. It is composed of quartz and feldspar, with small crystals of calcium carbonate embedded within it. The structure of a walkerite can vary depending on its location and exposure to weathering processes. Walkerites are named after the way they look when viewed under a microscope, which resembles the letter "W" in English. They are also known as quartzite or feldspathic quartzite