Borax Bead Tests

This table of flux fusion reactions with borax is based largely on the book "Determinative Mineralogy and Blowpipe Analysis" by Brush & Penfield, 1906. The reactions are observed by fusing a crushed (and roasted in the case of sulfides) sample of the mineral in a borax bead embedded on a loop of platinum wire. The color is observed in the bead after heating the sample with the oxidizing flame and then the reducing flame of the torch (blowpipe).

Oxidizing Flame		Amount of Material	Chemical Element(s)	Reducing Flame
HOT	COLD	Amount of Material	Chemical Element(s)	HOT	COLD
Colorless	Colorless	Little or Much	Si, Al, and Sn	Colorless	Colorless
Colorless	Colorless or opaque White depending on the degree of saturation	Little or Much	Ca, Sr, Ba, Mg, Be, Zn, Y, La, Th, Zr, Ta, and Nb	Colorless	Colorless or opaque White depending on the degree of saturation
Pale Yellow	Colorless or White	Much	Pb, Sb, and Cd	Pale Yellow	Colorless
Pale Yellow	Colorless or White	Much	Bi	Gray	Gray
Pale Yellow	Colorless or White	Much	Mo	Brown	Brown
Pale Yellow	Colorless or White	Medium	W	Yellow	Yellow to Yellowish Brown
Pale Yellow	Colorless or White	Medium	Ti	Grayish	Brownish Violet
Pale Yellow	Nearly Colorless	Little	Fe and U	Pale Green	Nearly Colorless
Yellow	Pale Yellow	Little	Ce	Colorless	Colorless
Yellow	Yellowish Green	Little	Cr	Green	Green
Yellow	Yellowish Green, almost Colorless	Little	V	Dirty Green	Fine Green
Deep Yellow to Orange-red	Yellow	Medium to Much	Ce	Colorless	Colorless
Deep Yellow to Orange-red	Yellow	Medium to Much	U	Pale Green	Pale Green to nearly Colorless
Deep Yellow to Orange-red	Yellow	Medium to Much	Fe	Bottle Green	Pale Bottle Green
Deep Yellow to Orange-red	Yellowish Green	Medium to Much	Cr	Green	Green
Green	Blue	Little to Medium	Cu	Colorless to Green	Opaque Red with much Oxide
Green	Yellow, Green, or Blue of various Shades	Medium	Various Mixtures of Fe, Cu, Ni, and Co	(?) See Below	(?) See Below
Blue	Blue	Little to Medium	Co	Blue	Blue
Violet	Reddish Brown	Little to Medium	Ni	Opaque Gray	Opaque Gray
Violet	Reddish Violet	Little	Mn	Colorless	Colorless
Pale Rose	Pale Rose	Much	Nd	Pale Rose	Pale Rose

Borax Bead Tests

Borax Bead Tests

Table of Reactions Obtained with Borax