Lead
Pb
atomic number
82
melting point
327.46°C

1. Using a platinum loop, heat a tiny amount of powdered mineral sample in the flame of a lamp, candle, or Bunsen gas burner; many lead-bearing minerals will produce a pale azure-blue flame that is tinged with green.

2. Mix a bit of powdered mineral sample with some sodium carbonate flux (a pinch of powdered charcoal mixed in at this stage enhances the results of the test but is not necessary), then place the mixture on a charcoal block and apply the blowpipe flame; a bright malleable bead of metallic lead will form with a smudge of yellow PbO nearby; the sublimate turns to a bluish-white stain further away from the assay.

3. Mix a bit of powdered mineral sample with three volumes of Von Kobell’s Flux, then place the mixture on a charcoal block and heat it with the oxidizing portion of the flame; a chrome-yellow sublimate that changes to greenish-yellow further from the assay will form on the charcoal block.

4. Dissolve some powdered mineral sample in a dilute nitric acid solution, then add a few drops of dilute H2SO4 or HCl (in this case, it doesn’t really matter; both produce a white precipitate); a white precipitate of PbSO4 will form if H2SO4 is used and a white precipitate of PbCl2 will form if HCl is used.