Name/Title
PyromorphiteEntry/Object ID
2004.1.46Description
Assemblage Zone: pegmatite dikes
Chemical Composition: Pb5(PO4)3Cl , Lead Chloro
Crystal System: Hexagonal System
Description: Common Name: Pyromorphite
Group Name: Apatite
Chemistry:Pb5(PO4)3Cl , Lead Chlorophosphate
Location: Dooping Mine, China
Guangxi Zhuang AR, China
Description: Lots of tiny green crystals on brown matrix. Looks like short grass.
PHYSICAL CHARACTERISTICS:
Color is typically green, but can also be yellow, orange and brown.
Luster is resinous to adamantine.
Transparency: Crystals are rarely transparent, but usually translucent.
Crystal System is hexagonal; 6/m
Crystal Habits include the typical barrel shaped hexagonal prism with the hexagonal pyramid and/or a pinacoid as a termination. A classic specimen of Pyromorphite shows its arborescent habit as described above. Also granular, reniform, encrusting and massive.
Cleavage is absent.
Fracture is uneven.
Hardness is 3.5 - 4.
Specific Gravity is approximately 7.0+ (very heavy for translucent minerals)
Streak is off white.
Associated Minerals are cerussite, limonite, galena and secondary lead deposit minerals.
Other Characteristics: Index of refraction is 2.05 (typically high for lead minerals) and crystal terminations can be hollowed out or pitted.
Best Field Indicators are crystal habit, color, lack of transparency and density.
Fracture: uneven
Hardness: 4 Fluorite
Luster: Resinous
Occurrence: Pyromorphite is a mineral species composed of lead chlorophosphate: Pb5(PO4)3Cl, sometimes occurring in sufficient abundance to be mined as an ore of lead. Crystals are common, and have the form of a hexagonal prism terminated by the basal planes, sometimes combined with narrow faces of a hexagonal pyramid. Crystals with a barrel-like curvature are not uncommon. Globular and reniform masses are also found. It is part of a series with two other minerals: mimetite (Pb5(AsO4)3Cl) and vanadinite (Pb5(VO4)3Cl), the resemblance in external characters is so close that, as a rule, it is only possible to distinguish between them by chemical tests.
Notable Occurrences include Idaho and Pennsylvania, USA; Mapimi, Mexico; Germany; England and Australia.
Rock Type: Sedimentary
Specific Gravity: 3.5-4
Streak: white
Variety: Pyromorphite shares the same structure with apatite and therefore crystals of the two will have similar shapes. Pyromorphite also forms a chemical series with two other minerals; Mimetite (Pb5(AsO4)3Cl) and Vanadinite (Pb5(VO4)3Cl). This series is a little different than most chemical series which involve substitution of cations such as calcium for magnesium. Instead, this series substitutes its basic chemical units the anion groups; phosphate (PO4), arsenate (AsO4) and vanadate (VO4). Green Mimetite or yellow Pyromorphite can make identification between the two difficult, but usually pyromorphite is green and mimetite is yellow. Vanadinite is usually red. Pyromorphite's main characteristic is its unique crystal habit of stacked barrel shaped crystals that branch out in a way that is reminescent of some branching cactus varieties.Collection
Suomynona Mineral Collection, Suomynona CollectionAcquisition
Accession
2004.1Source or Donor
Suomynona Mineral CollectionAcquisition Method
DonationDimensions
Width
16 inDepth
10 inLength
12 inDimension Notes
Dimension taken at widest pointsLocation
Location
Display Case
FS-3-ARoom
Frieda Smith HallBuilding
Crater Rock MuseumCategory
ExhibitMoved By
Jillian Mather KettleyNotes
Location/ inventory
