Pyromorphite
Pyromorphite is a lead phosphate mineral prized for its bright green to yellow-green color and barrel-shaped hexagonal crystals. It is dense, has a resinous luster, and forms in the weathered upper zones of lead deposits.
Pyromorphite properties at a glance
| Type | Phosphate Minerals |
|---|---|
| Chemical formula | Pb5(PO4)3Cl |
| Mohs hardness | 3.75 |
| Crystal system | hexagonal |
| Luster | resinous |
| Streak | White |
| Cleavage | Poor |
| Fracture | Subconchoidal |
| Specific gravity | 7 |
| Transparency | translucent |
| Common colors | Green, Yellow-green, Yellow, Brown, Orange |
| Rarity | uncommon |
Geology & background
Pyromorphite forms in the oxidized zones of lead ore deposits, where lead-bearing minerals react with phosphate-rich solutions to crystallize this secondary mineral.
Pyromorphite has been recognized since early mineralogy as a colorful secondary lead mineral, and it served historically as a minor ore of lead in some weathered deposits.
How to identify Pyromorphite
- Look for bright green to yellow-green barrel-shaped hexagonal crystals in colorful crusts.
- Pyromorphite feels heavy for its size because of its high lead content and has a resinous luster.
- It occurs in oxidized lead deposits with cerussite and galena, which helps confirm identification.
Where Pyromorphite is found
Pyromorphite occurs in oxidized lead deposits worldwide, with notable specimen localities in Germany, France, China, the United States, England, and Australia.
How much is Pyromorphite worth?
| Entry-level specimen | $15 |
|---|---|
| Typical collector specimen | $90 |
| Premium specimen | $600+ |
Value depends on color, crystal size and form, luster, locality, matrix, and overall condition.
Common uses
- Minor ore of lead
- Collector specimens
- Educational mineral examples
- Display pieces
Interesting facts
- Pyromorphite often grows as stubby, barrel-shaped hexagonal crystals in colorful crusts.
- Its name comes from Greek words for fire and form, because a melted globule recrystallizes on cooling.
- It forms a chemical series with mimetite, which contains arsenic in place of phosphorus.
- Its high lead content gives pyromorphite a noticeably heavy feel for its size.
Care & safety
Pyromorphite is soft and somewhat brittle, so slender crystals chip and break easily.
Contains lead. Pyromorphite is a lead mineral; wash hands after handling and never cut or grind it without proper protection.
