| Compounds of boron (Arabic Buraq from Persian Burah from Turkish Bor) have been known of for thousands of years. Burah was used as flux agent for gold and silver soldering as well as to fluidify glass and glaze fluidity in glassmaking. In the beginning of 17th century a substance was disengaged from burah which was called boronic acid. In 1808, Joseph Louis Gay-Lussac, and Louis Jacques Thenard, and shown up 9 days later Sir Humphry Davy announced about the discovery of a new element. It was separated by the reduction of boric acid baking it with metal potassium which was discovered by Humphry Davy shortly before. After separating the element the French chemists called the new element le bore and Davy called it boron (from Latin Boron), the name which is used in English now. In the beginning of 19th century Russian chemists gave various names to it, however nowadays it is called "bor". |
According to A.P. Vinogradov the boron clarke in the Earth's crust is 1.2x10-3%, mostly in clays and clay-slates (1.1x10-2%), in phosphorites (1.3x10-2%), ferro-manganese\xC2\xA0nodules (1.1x10-2%), kimberlites (1.9x10-2%) as well as in underground water of volcanically active areas, petroleum water, gypsum-anhydrite salt-bearing masses and mud volcanoes. Approximately 160 boron minerals are known at the present time; most of them are sodium, potassium, magnesium and calcium borates, also well-known borosilicates, boroalumosilicates and other mineral groups.
Boron may be deemed as a nominally essential microelement, because it is always present in human body even though in negligibly small amounts. In fact the biological significancy of boron is not fully understood. Some recent findings indicate that boron participates in the metabolism of calcium, magnesium and phosphorus, and the deficiency of boron and magnesium caused detrimental changes in the bones. However the daily requirement ofboron for human beings is not determined yet. Anyway the fact that there is no boron deficiency in human body is certainly comforting. |