Jeweller’s borax

Jeweler s borax, see Sodium tetraborate 10-water Jeweler s rouge, see Iron(III) oxide... 

Commercially available sodium borate decahydrate is usually present as monoclinic prismatic crystals that become opaque on the surface in dry air. In addition to the decahydrate, a pentahydrate exists this is also known as jeweller s borax. The anhydrous substance is also available and is called pyroborax. The EINECS number for sodium borate is 271-536-2. 

Trigonal crystals. Also called jeweler s borax or, incorrectly, octahedral borax. At temperatures above 88°C at 10 mm. it converts to the dihydrate, d 1.81. 

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See also in sourсe #XX -- [ ]

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