The word “basalt” is ultimately derived from Late Latin basaltes, misspelling of L. basanites “very hard stone”.The mineralogy of basalt is characterized by a preponderance of calcic plagioclase feldspar and pyroxene. Olivine can also be a significant constituent. Accessory minerals present in relatively minor amounts include iron oxides and iron-titanium oxides, such as magnetite, ulvospinel, and ilmenite. Because of the presence of such oxide minerals, basalt can acquire strong magnetic signatures as it cools, and paleomagnetic studies have made extensive use of basalt. Basalt can be used for flooring, countertops, window sills and wall covering. It is also used in road construction (in aggregates), and can be ground into a powder and converted to a heat-resistant fiber. It can be used to strengthen concrete and to add to the fire-resistant properties of gypsum board.