Note 2 — Chapter XVII · BORON, ALUMINIUM, AND THE ANALOGOUS METALS OF THE THIRD GROUP

We may mention the following among the minerals which contain boron: calcium borate, (CaO)3(B2O3)(H2O)6, found and extracted in Asia Minor, near Brusa; boracite (stassfurtite), (MgO)6(B2O3)8,MgCl2, at Stassfurt, in the regular system, large crystals and amorphous masses (specific gravity 2·95), used in the arts; ereméeffite (Damour), AlBO3 or Al2O3B2O3, found in the Adulchalonsk mountains in colourless, transparent prisms (specific gravity 3·28) resembling apatite; datholite, (CaO)2(SiO2)2B2O3,H2O; and ulksite, or the boron-sodium carbonate from which a large quantity of borax is now extracted in America (Note 1). As much as 10 p.c. of boric anhydride sometimes enters into the composition of tourmalin and axinite.