A System of Instruction in the Practical Use of the Blowpipe Part 38

Mineral. Chromic iron

Formula. [.Fe][...Cr=].

Behavior

(1) in gla.s.s-bulb. --

(2) in open tube. --

(3) on charcoal. --

(4) in forceps. As the preceding.

(5) in borax. Dissolves slowly and gives the chromium reaction.

(6) in mic. salt. As in borax.

(7) with carb. soda. On platinum foil with nitre and carbonate of soda affords a yellow ma.s.s of chromate of pota.s.sa.

(8) Special reactions. --

Mineral. Lievrite

Formula. 3([.Fe][.Ca])^{3}[...Si] + 2[...Fe=][...Si].

Behavior

(1) in gla.s.s-bulb. Occasionally gives off some water and turns black.

(2) in open tube. --

(3) on charcoal. Fuses to a black globule, which in the reducing flame becomes magnetic.

(4) in forceps. I. In reducing flame is magnetic.

(5) in borax. Gives the iron reaction.

(6) in mic. salt. Gives the iron and silica reactions.

(7) with carb. soda. Fuses to a black opaque bead.

(8) Special reactions. Generally gives the manganese reaction with nitre and carbonate of soda.

Mineral. Chloropal

Formula. [...Fe=][...Si]^{2} + 3[.H].

Behavior

(1) in gla.s.s-bulb. Decrepitates more or less, gives off much water and turns black.

(2) in open tube. --

(3) on charcoal. --

(4) in forceps. V. Loses color and turns black.

(5) in borax. Gives the iron reaction.

(6) in mic. salt. Gives the iron and silica reaction.

(7) with carb. soda. Fuses to a transparent green gla.s.s.

(8) Special reactions. --

Mineral. Green earth

Formula. [...Si],[.Fe],[...Al=],[.Na],[.K],[.H], etc.

Behavior

(1) in gla.s.s-bulb. Gives off water and becomes darker in color.

(2) in open tube. --

(3) on charcoal. --

(4) in forceps. V. In reducing flame fuses on edges and colors the outer flame yellow ([.Na]) or violet ([.K]).

(5) in borax. As the preceding.

(6) in mic. salt. As the preceding.

(7) with carb. soda. Forms a slaggy ma.s.s.

(8) Special reactions. --

Mineral. Siderite

Formula. [.Fe][..C].