Feldspar Feldspar Feldspars (KAlSiO – NaAlSiO – CaAlSiO) are a group of rock-forming tectosilicate minerals that make up about 41% of the Earth's continental crust by weight. Feldspars crystallize from magma as veins in both intrusive and extrusive igneous rocks and are also present in many types of metamorphic rock. Rock formed almost entirely of calcic plagioclase feldspar (see below) is known as anorthosite. Feldspars are also found in many types of sedimentary rocks. The name "feldspar" derives from the German "Feldspat", a compound of the words "Feld", "field", and "Spat", "a rock that does not contain ore". The change from
Salting the earth Salting the earth Salting the earth, or sowing with salt, is the ritual of spreading salt on conquered cities to symbolize a curse on their re-inhabitation. It originated as a symbolic practice in the ancient Near East and became a well-established folkloric motif in the Middle Ages. The custom of purifying or consecrating a destroyed city with salt and cursing anyone who dared to rebuild it was widespread in the ancient Near East, but historical accounts are unclear as to what the sowing of salt meant in that process. Various Hittite and Assyrian texts speak of ceremonially strewing salt, minerals,