Formula.  ZnS.

Behavior

(1) in glass-bulb.  Decrepitates strongly.

  (2) in open tube.  Evolves SO and becomes white or yellow if
                         containing iron.

  (3) on charcoal.  V. In the reducing flame incrusts the charcoal
                         with ZnO; also with CdO, if that metal be
                         present.

  (4) in forceps. —­

  (5) in borax.  The roasted mineral gives a zinc reaction, and
                         sometimes a slight iron reaction.

  (6) in mic. salt.  As in borax.

  (7) with carb. soda.  As alone on charcoal.  Moreover colors the flame
                         blue.  The fused alkali gives a S reaction on
                         silver.

  (8) Special reactions. —­

* * * * *

Mineral.  Red oxide of zinc

Formula. [.Zn].

Behavior

  (1) in glass-bulb. —­

  (2) in open tube. —­

  (3) on charcoal.  In the reducing flame forms a thin incrustation
                         of oxide of zinc on the charcoal.

  (4) in forceps.  V.

  (5) in borax.  Generally gives a manganese and slight iron
                         reaction in addition to that of zinc.

  (6) in mic. salt.  As in borax.

  (7) with carb. soda.  On charcoal, forms a thick incrustation of ZnO.

  (8) Special reactions.  With carbonate of soda and nitre on platinum
                         foil gives manganese reaction.

* * * * *

Mineral.  Electric calamine

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

Behavior

  (1) in glass-bulb.  Gives off water and becomes white and opaque.

  (2) in open tube. —­

  (3) on charcoal. —­

  (4) in forceps.  V.

  (5) in borax.  Dissolves to a clear glass, which cannot be
                         rendered opaque by the intermittent flame.

  (6) in mic. salt.  Dissolves to a clear glass, which becomes opaque
                         on cooling.  Silica remains insoluble.

  (7) with carb. soda.  With carbonate of soda alone is infusible.  With
                         2 parts of alkali and 1 of borax fuses to a
                         glass and sets free [.Zn], which incrusts the
                         charcoal.

  (8) Special reactions. —­

* * * * *

Mineral.  Calamine

Formula. [.Zn][..C].

Behavior

  (1) in glass-bulb.  Gives off CO^{2} and becomes opaque.