Jamesonite is a sulfosalt mineral with formula Pb4FeSb6S14.
An important occurrence of Jamesonite in Quartz is from Pitangui, Belo
Horizonte, Minas Gerais, Brazil. It is found in the sames quartz crystals
that produce Ankangite (Mannardite) and Celsian inclusions (see).
Some Jamesonite crystals appear to be partially or totally replaced
by yet undetermined Sb white-yellow alteration minerals, that can be Valentinite
or Cervantite. Associated with jamesonite have been found also small, clear,
tabular crystals of Fluorapatite and the very rare mineral Cebaite (Ba3Ce2(CO3)5F2).
This paragenesis is younger than ankangite-celsian because it grows in
a higher portion of the quartz crystals.
Left: Quartz crystal with Jamesonite phantom and Ankangite crystals
near the base. Center: Jamesonite. Right: Altered Jamesonite in possibly
Valentinite or Cervantite.