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