THE MINERAL MENEGHINITE

  • Chemistry: Pb13Sb7S23, Lead Antimony Sulfide
  • Class: Sulfides
  • Subclass: Sulfosalts
  • Uses: Mineral specimens and as a very minor ore of lead.
  • Specimens

Meneghinite is a rare mineral that generally forms interesting acicular crystals. Meneghinite is one of several lead antimony sulfides. The elements lead, antimony and sulfur have the capability of forming many different minerals. There are at least a dozen different minerals with just lead, antimony and sulfur comprising their chemistries. All of those minerals are sulfosalts, a segment of sulfides where the antimony acts more like a metal than a non-metal and occupies a position where it is bonded to sulfurs. They have some very similar properties such as a gray color, high density, low hardness, metallic luster, dark gray to black streaks and a similar environment of formation. Most form from hydrothermal fluids that crystallize at lower temperatures than other sulfides. They can be distinguish only by differences in their respective crystal habits, cleavages, fracture and x-ray techniques. The table below shows most of the lead antimony sulfides and their formulas (some have additional elements).

MINERAL FORMULA MINERAL FORMULA MINERAL FORMULA
ANDORITE PbAgSb3S6 BOULANGERITE Pb5Sb4S11 FREIESLEBENITE PbAgSbS3
FULOPPITE Pb3Sb8S15 GEOCRONITE Pb14(Sb, As)6S23 GUETTARDITE Pb(Sb, As)2S4
HETEROMORPHITE Pb7Sb8S19 JAMSONITE Pb13FeSb7S23 LAUNAYITE Pb22Sb26S61
MENEGHINITE Pb13Sb7S23 PARAJAMSONITE Pb4FeSb7S23 PLAGIONITE Pb5Sb8S17
PLAYFAIRITE Pb16Sb18S43 ROBINSONITE Pb4Sb6S13 SEMSEYITE Pb9Sb8S21
SORBYITE Pb19(Sb, As)20S49 TWINNITE Pb(Sb, As)2S4 ZINKENITE Pb9Sb22S42

PHYSICAL CHARACTERISTICS OF MENEGHINITE:

  • Color is lead gray to black.
  • Luster is metallic.
  • Transparency: Crystals are opaque.
  • Crystal System: Orthorhombic: 2/m 2/m 2/m.
  • Crystal Habits include common acicular to prismatic, granular and even some fibrous crystals and massive forms.
  • Cleavage is perfect in one direction (prismatic).
  • Hardness is 2.5
  • Specific Gravity is 6.3 - 6.4 (heavier than average for metallic minerals)
  • Streak is steel gray.
  • Associated Minerals include calcite, galena, sphalerite, tetrahedrite, arsenopyrite and several other sulfosalts.
  • Notable Occurrences include the type locality of Bottino Mine, Serravezza, Alpe Apuane, Toscana, Italy as well as Chamonix Valley, France; Turkey; Kalkar Quarry, Santa Cruz County, California, USA and Marble Lake, Frontenac County, Ontario, Canada.
  • Best Field Indicators are crystal habit, associations, cleavage, locality and density.
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Available MENEGHINITE specimens:
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