Apatite is a group of phosphate minerals, usually referring to hydroxylapatite, fluorapatite and chlorapatite, with high concentrations of OH−, F− and Cl−ions, respectively, in the crystal. The formula of the admixture of the four most common endmembers is written as Ca10(PO4)6(OH,F,Cl)2, and the crystal unit cell formulae of the individual minerals are written as Ca10(PO4)6(OH)2, Ca10(PO4)6(F)2 and Ca10(PO4)6(Cl)2.
The mineral was named apatite by the German geologist Abraham Gottlob Werner in 1786, although the specific mineral he had described was reclassified as fluorapatite in 1860 by the German mineralogist Karl Friedrich August Rammelsberg. Apatite is a mineral that is often mistaken for other minerals. This tendency is reflected in the mineral's name, which is derived from the Greek word απατείν (apatein), which means to deceive or to be misleading.
Apatite is one of a few minerals produced and used by biological micro-environmental systems. Apatite is the defining mineral for 5 on the Mohs scale. Hydroxyapatite, also known as hydroxylapatite, is the major component of tooth enamel and bone mineral. A relatively rare form of apatite in which most of the OH groups are absent and containing many carbonate and acid phosphate substitutions is a large component of bone material.
Baby, everything is all right, uptight, out of sight
Baby, everything is all right, uptight, out of sight
I'm a poor man's son, from across the railroad tracks,
the only shirt I own , is hanging on my back,
but I'm the envy of every single guy
since I'm the apple of my girls eye
when we go out stepping on the town.
For a while my money's low,
and my suit's out of style, but it's all right
if my clothes aren't new,
out of sight, because my heart is true,
she says baby everything is all right,
uptight, out of sight, baby everything is