Mineralpedia Details for Pyromorphite

In reference to Pyromoprhite’s physical property of recrystallizing after melting, it is named for the Greek pyr, “fire” and morph, “form.” Found in hundreds of localities, Pyromorphite is a secondary mineral that forms in oxidized lead deposits, and can form, albeit rarely, as a volcanic sublimate. Pyromorphite can be piezoelectric, generate a charge in response to pressure, provided it is biaxial. Will needle occasionally fluoresce yellow-orange under long-wave and short-wave ultraviolet light. Pyromorphite occurs as crystals with a hexagonal outline, which are typically columnar or barrel-shaped. Also occurs as crusts or mammillary aggregates. Prominately green or yellow, but also brown, gray, orange, translucent. 

Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/pyromorphite.pdf

Formula

Pb₅(PO₄)₃Cl 

Crystal System

Hexagonal 

Crystal Habit

Crystals short to long prismatic, acicular, often hoppered terminations, rarely tabular to equant; radiating to branching groups, tapering to a point. Commonly rounded, globular, reniform, botryoidal. 

Cleavage

On {1011}, interrupted 

Luster

Resinous to subadamantine 

Color

Dark grass-green, green, yellow, yellow-orange, reddish orange, yellow-brown, brown, tan, grayish, may be colorless 

Streak

White 

Geological Setting

A secondary mineral in the oxidized zone of lead deposits 

Class

Hexagonal, 6/m - Dipyramidal 

Fracture

Uneven to subconchoidal 

Hardness

3.5–4 

WebMineral

View Pyromorphite 

Mindat

View Pyromorphite 

Lime green barrel shaped crystals to 7mm.

Greenish yellow 0.75 to 1mm curved or barrel-shaped crystals.

Glassy light dark green prismatic crystals to 1mm.

Barrel shaped brownish colored crystals to 6mm.

Grass green acicular crystals in radial sprays to 6mm.

Dark green barrel shaped crystals to 3mm with slightly lighter green terminations.

Excellent, green to yellow hexagonal crystals to about 1mm.

Bright green, acicular to tiny prismatic Pyromorphits crystals covering most of matrix.

Lime green tapering hexagonal crystals, the largest to 1cm and averaging 3mm.

Green yellow crystals of prismatic and hexagonal Pyromorphite to 3mm. Fairly good specimen from this classic English locality.

Acicular, hexagonal crystals to mostly 3mm randomly oriented on Quartz matrix. The crystals are tapered to a point and some show hopperd growth habit.

Bright yellow micro, acicular crystals of Pyromorphite covering Galena matrix with clear to white Cerussite crystals to 2mm.

Orange crystals of acucular Pyromorphite crystals to less than 1mm in clusters occupying every nook and cranny of this specimen. It is totally all Pyromorphite. 

Bright green carpet of Pyromorphite clusters composed of tiny hexagonal crystals in radial growths.

Specimen is covered with Pyromorphite from a smooth, melted-looking habit to well-defined individual, hexagonal crystals to 1mm. Some of the prismatic crystals are tipped with a second generation and slightly different color.

Botryoidal crystals of Pyromorphite to 2mm showing at least three growth phases which have resulted in slightly different crystal habits from a rich yellow composed of individual prismated crystals to a light yellow and sugary to a smooth translucent yellow. 

Glistening botryoidal crystals lining vuggy Quartz matrix.

Light green balled-up Pyromorphite crystals with overgrowths of darker green crystals and other areas with acicular grass green micro crystals.

Bright green acicular Pyromorphite crystals to 1mm with good coverage throughout matrix.

Lime green crystal aggregates with no particular forms to 2mm.

Special Info

Phillips Collection

Nice, lustrous bright-orange Pyromorphite in curved crystals giving the piece a sparkly botryoidal look.

Also: greenish yellow, nice barrel-shaped crystals to 5mm i

Vibrant yellowish green acicular and prismatic crystals with good coverage.

Cluster of brownish Pyromorphite crystals to 4mm with a silvery luster and cream-colored terminated end.

Barrel shaped grrenish-yellow crystals to 1cm.

Colorless acicular Pyromorphite crystals to 3mm. Good locality specimen.

Yellow micro crystals to about 0.5mm across face.

Green barrel-shaped crystals to 2mm.

Greenish prismatic crystals with yellow tips to 4mm.

Grass green prismatic crystals to 5mm. 

Lustrous tan Pyromporphite crystals to 5mm. Good coverage in the many voids and crevices of this cabinet specimen.

Dark green Pyromorphite crystals less than 0.75mm with red prismatic crystals of Crocoite on one side and tabular Crocoite crystals on the other.  Colorful specimen! This is a hard combination to get - they are out there but usually not of this quality.